Month: February 2023

Multimedia models for ENMs can predict environmental concentrations based on sources of continuous, time dependent, or episodic releases and are similar to multimedia models that predict environmental concentrations of organic chemicals and particle associated organic chemicals.For ENMs, predicting particle size distribution as affected by particle dissolution, agglomeration, and settling is desired for various spatial and temporal end points. For one integrated MFA and multimedia model , user defined inputs are flexible around product use and ENM release throughout material life cycles.It is noted that although validation of multimedia models is a formidable task, various components of such models have been validated as well as model predictions with such models for particle bound pollutants. Most far field models of ENMs have major challenges. First, the quantities and types of ENMs being manufactured are unknown to the general public due to issues surrounding confidential business information, leading to a reliance on market research.The resulting public uncertainty will persist while nanotechnology continues a course of rapid innovation, as is typical of new industries.The rates of product use and ENM releases at all life cycle stages are also not defined.There are challenges associated with modeling transport processes through specific media and across media , highly divergent time scales of processes, lack of required input parameters, and the need for validation of results .Several multimedia models developed for conventional chemicals could be adapted around ENMs,vertical grow but few account for fate processes specific to nanoparticles .In addition, various transport models for a single medium and in the multimedia environment could be adapted for far field analysis of ENMs, but few account for fate processes distinctive to ENMs .

Moreover, their validation, which would require ENM monitoring data, is a major challenge. The lack of understanding of many fundamental ENM behaviors under environmental conditions propagates into broad uncertainties, for example in predicting ENM removal to solids or aqueous fractions in WWTPs.ENM surface chemistries fundamentally affect ENM agglomeration or dispersion and likely affect bio availabilty.Some species on ENM surfaces may degrade in the environment,while other adsorbates can be acquired.Carbonaceous ENMs may be transformed or degraded by environmental processes such as photo,enzymatic,chemical,and bio degradation.Redox and other environmental conditions will affect nanomaterial surfaces, which for nano Ag includes formation of sulfide that inhibits dissolution.Surface chemistry also affects transformation rates of primary particles and aggregates .For many ENMs such as nanoceria,reactivity is highly size dependent. To accurately model material fates thus requires understanding how material surface properties affect integrity, how both change under varying environmental conditions such as pH, clay content,and organic matter content, and how surface properties and particle reactivity affect physicochemical processes that are parametrized in far field models. This is especially true for ENMs used as pesticide delivery mechanisms, including carbon nanotube composites with specifically reactive surface monomers. Yet only recently has modeling attempted to address differing properties of a material’s structural variants .Evaluating computational model predictions is a challenge for ENMs, which presently are estimated to occur in the environment at low concentrations.Also, detection methods for ENMs in environmental media and distinguishing ENMs from natural chemical analogs are still under development,with more evaluation strategies needed including a framework for validating new ENM analytical detection methods.

Fullerenes from incidental sources were quantified in river sediments collected from locations across the globe and quantified in the atmosphere over the Mediterranean Sea.Perhaps related to a viable exposure scenario, fullerenes were quantified at relatively high concentrations in treated wastewater effluent and at ng/L to μg/L concentrations in river waters receiving effluent discharge. While not necessarily nanoscale, similarly high concentrations of TiO2 were reported for sediments sampled near a WWTP outfall.The greatest uncertainty in ENM exposures is near field , at the receptor where toxicant dose manifests as internal dose. Heteroaggregation is a dominant fate process for ENMs when they interact with natural colloids.Given sufficient residence time for ENMs in environmental matrices, heteroaggregation and to a lesser degree homoaggregation will affect localized compartmentalization, including stability in the water column and therefore, sedimentation.However, these processes do not preclude biological impacts under simulated environmental conditions, as has been shown for nanoceria in a complex aquatic mesocosm.Exposure can be confirmed by quantifying receptor body burdens, thereby allowing for quantitatively relating near field exposure to biological effects.Thus, in the absence of detailed, biologically complex, near field models for local exposures to environmental receptors, the ability to trace ENMs to biological receptors sampled directly from the environment becomes the best available approach to relate far field exposures to biological impacts.Overall, material flow models and multimedia modeling of ENMs have advanced to inform ENM ecotoxicology. Available far field modeling frameworks are adaptable to changing inputs despite uncertainties in production volumes. Major uncertainties remain at the nexus of ENM surface and core chemistries as related to nanomaterial transport, aggregation, and degradation characteristics.

However, fundamental research is needed to discover and parametrize complex fate processes. New approaches, such as assays that can be used to rapidly probe surface associations,demonstrate how to populate far field models and how to determine near field exposures associated with effects. Although existing models can simulate particle movement, deposition, and some transformations, the knowledge state regarding ENM environmental exposure conditions via measurements or modeling simulations cannot be assumed to accurately represent actual conditions at biological receptors.Many of the outstanding research issues and recommendations for evolving ENM ecotoxicology are echoed in the discourse for other chemicals of emerging concern .These include the need for systematically understanding ENM and decomposition product toxicity across various receptors within linked levels of biological organization,quantifying actual exposures and uptake into environmental receptors,gaining mechanistic insights into and biological markers for acute and chronic low level exposures,and understanding how environmental factors including cocontaminants affect ENM transformation and biological impacts. Still, how can the potential for exposure and impacts of ENMs be anticipated, prevented, managed, or mitigated? Further, what data and tools do decision makers need to inform their work? While no formalized process for incorporating all exposure conditions and concepts of ENM transformation, dose, and body burden into risk assessments currently exists, a proposed framework approach to risk characterization over the life cycle of ENMs has been published and is available.This framework advocates an initial decision cutoff in regards to exposure; in the absence of exposure,indoor growers the need for further assessment is diminished or negated.In this available framework, ENMs that are certain to rapidly dissolve into ionic components in a destined environmental compartment would be assessed for risk based on the released components rather than the original nanoparticles.Persistent ENMs are expected to accumulate in matrices such as sediments.The consequences of ENMs to successive generations, biodiversity, and ecosystem services are not addressed by model organism specific assays of discrete growth and mortality.Nonetheless, in this available framework, toxicity end points associated with standardized testing protocols for sediment, aquatic, and terrestrial standard population level end points over short and long time frames are advocated for assessing hazards of simulated ENM concentrations in the environment.In this framework, sunlight is an environmental variable, bio accumulation is measured, and ENM modifications during product and material life cycles that may change bio availability are considered.While such a framework has broad organizational appeal, priority setting within the framework is required and thus could focus on tests that are relatively well aligned with likely exposure scenarios. Even with a risk assessment framework that considers ENMs across product life cycles and considers sediments, water, and soil in testing end points,major hurdles hinder regulatory agencies, and research scientists, in using concepts such as exposure conditions, ENM transformation, dose, and body burden in interpreting biological and computational findings for assessing risks. Toxicity tests developed for dissolved chemicals typically require significant modification for use with ENMs.Tests may not apply to ENMs if they are not appropriate for solids.Additional scientifically based hazard information from the peer reviewed literature may or may not be available for consideration. ENMs used in ecotoxicity tests, which are sometimes laboratory synthesized to overcome uncertainty regarding proprietary coating or other commercial formulations, may be insufficiently analogous to allow for extrapolating information or risk comparisons.

Issues include the need to know test material characteristics and how they relate to testing results and the ENM life cycle. Even if an initial risk assessment considers ENM solubility,ENM dissolution is not instantaneous; therefore, at what stage of dissolution does the contaminant no longer pose a hazard as an ENM? Also, where biological impacts stem from ENM surface characteristics, how can mass concentration be used to judge hazards? Environmental ENM effects in benchtop experiments can be indirect, stemming from physical nutrient depletion,or amplifying organism uptake of cocontaminants.Other indirect physical effects derive from ENMs adhering to the organism surface,light shading,or internal food displacement.Near field exposures can result in biological hazards from specific ENMs based on their properties .By definition, ecological risk assessment is “the process for evaluating how likely the environment will be impacted as a result of exposure to one or more environmental stressors.”ERA involves predicting effects for individuals, populations, communities and ecosystems, and concerns itself with valuable ecosystem services such as nutrient cycling.Thus, conducting ERAs for ENMs could benefit from an ecological outlook. All levels of biological organization, and interactions between them, would be considered when assessing responses to ENM exposure . Release and exposure scenarios , use of functional assays for assessing environmental compartmentalization ,and combined life cycle and multimedia modeling have important roles in focusing ENM ecotoxicology. Less recognized is that mechanistically based models of dynamic biological effects are informed by hazard assessment research. Different types of process based, dynamic models allow for predicting effects from exposures stepwise, starting at sub cellular levels, into individuals, through populations, and conceivably to communities and ecosystems. Developing process based models requires researching key effects processes and ecological feedbacks.Models are formalized to describe interactive processes culminating in toxicity such as reactive oxygen species generation and cellular damage. Process based mathematical expressions evolve with empirically based discoveries or through model reconciliation with experimental data. Parameters are independent of toxicity testing protocols, although models could be informed by standard test results. Thus, ENM ecotoxicity research could support predictive toxicology by informing and populating process based, dynamic ecological effects models. A comprehensive fate and effects research agenda is needed for addressing ENM quantification in complex media.Such an agenda has allowed for assessing experimental compartmentalization,and sensitively assessing environmental persistence,toxicity, bio accumulation,trophic transfer,and indirect effects from the uptake of ENMs coated in other hazardous materials.Such research could substantially inform ENM risk assessment for a relevant environmental exposure scenario. However, most ENMs have not been studied comprehensively along the entire exposure and effects continuum . Further, the approach is not sustainable. Rather, the need is to develop efficient approaches applicable within an overall approach to rapidly evaluate the large number of ENMs under commercialization . A research agenda that focuses on distilling key determinants of exposure and hazard for ENM environment systems that can be measured experimentally would be most compelling. Thus, while the science of ENM ecotoxicology and exposure characterization has advanced, there are disconnects between how regulators review ENM based products for environmental safety and the research that is conducted to evaluate hazards. Except for results published in open source outlets or directly reported, research may be unknown to government bodies. Ongoing synthesis of published research results is challenging due to high variability across study conditions and ENMs tested, and due to effort needed to regularly update such comparisons. Moreover, there is a systematic resistance to publishing “no effect” studies in the peer reviewed literature.As a result, relying only on published research to inform regulatory decisions can present challenges. A life cycle based framework facilitates exposure modeling and hazard testing to support risk assessment. However, extrapolation of effects to untested concentrations, study, or environmental conditions, and across biological levels of organization, requires understanding dynamic biological process based effects, which current standard tests neither deliver nor sufficiently inform. Ultimately, exposure scenarios are useful for framing and focusing ENM ecotoxicology, and some version of a tiered intelligent testing and risk assessment strategy is needed. Such a conceptual tiered strategy considering the impact of the ENMs’ varying properties on ecological risks at different life cycle stages was proposed in the EU FP7MARINA project and is being further developed in the EU NANoREG program.

On the strength of these narratives, they can cultivate support at home for laws of return or flexible citizenship regimes, or seek support abroad from diaspora nationalist communities. It is not a given that these stories will be accepted or acted upon, but it is clear that sometimes they are, to dramatic effect. When differentiating between transnational practices undertaken for purely practical economic interests and those undertaken for religious, ethnic, or identity-based reasons becomes difficult, it becomes yet more important to recognize how the reality of diaspora and the myth of diaspora can be used to move people, money, and ideas in ways that simple labor forces never could. Following S, person after person told me similar things about their fear and dislike of their future Arab neighbors, and a few also told me that they would prefer to live outside of the increasingly Latino neighborhoods springing up in Beersheba, Ramla, and Tel Aviv. How did my subjects learn about the Israeli/Palestinian conflict, and how did they learn to place themselves so firmly against the Arab side of it? Why are they all ending up in Ramla anyway? Why in the world should their fellow Latin American Jews be lumped in with Palestinians as people to avoid once they make aliyah? And what does their curious, tenuous position tell us about the way race and immigration operate in Israel? Obviously, people exist outside and beyond this divide; the binary is only a politically expedient assumption. Even within the Jewish “side,” perceived race is predicated on a complicated and nuanced set of associations between different Jewish groups, affected by skin color, religious practice, language, and former national origin, among other aspects. Iquiteño Jews fall firmly on the Jewish side of that foundational split,stackable planters but they fit uncomfortably within that side. In this strange position, they highlight a fundamental Israeli paradox.

Secular nationalists in Israel need Jews to outnumber Palestinians within its territory, and so Israel constantly desires new Jewish bodies. To get them, it broadcasts a welcoming face to the diaspora, encouraging immigration under the Law of Return. This desire, however, must contend with powerful ultra-Orthodox gatekeepers that disapprove of conversion into any kind of non-Orthodox Judaism, and with the racism of other secular-nationalist Israeli Jews.However, they are not Jewish in the right or the most desirable ways. As they make their way to Israel, they must jump through administrative and religious hoops to please both sides, and along they way, they form their own opinions about their identities, Israeli racial hierarchies, and Jewishness itself. The case of Iquiteño Jewish migration is proportionally tiny, but it handily reveals Israel’s tenuous balancing act between secular-nationalist and ultra-Orthodox politics, and highlights the fragility and arbitrariness of the definition of Jewishness that Israel relies upon. Howard Winant and Michael Omi’s definition of a racial project is useful in discussing the creation of Israel’s racial system. A racial project is “is simultaneously an interpretation, representation, or explanation of racial identities and meanings, and an effort to organize and distribute resources along particular racial lines”. Omi and Winant often fail to see the ways in which religion becomes racialized, or the overlap between religion and ethnicity , unfortunately. Such an intersection is easy enough to fill in after the fact, particularly with the help of the clear example laid out before Iquitos. The state of Israel knowingly and actively pursues a racial project that privileges Ashkenazi religious and cultural behavior alongside phenotypical representations of race. In order to bridge this gap, I use Orna Sasson Levy’s work to describe how sub-ethnic differences within the Jewish population rub up against racial differences, as well as Yehouda Shenhav’s discussion of “Arab Jews” , which complicates the assumed simplicity of the Israeli/Palestinian divide. The end result is a racial project that hides the real complications of identity in Israel from vital prospective citizens.

Israel’s multi-part racial hierarchy privileges an ideal Jew who is pale-skinned, descended from European Jewish immigrants, observant and Orthodox enough for civil benefits but not too Orthodox18, and Ashkenazi in practice and culture. For those of Israel’s Jewish population who do not fit this mold, a complex hierarchy exists between different Jewish groups, forming a two part intra-Jewish racial structure where both perceived race and Jewish sub-ethnicity can be vectors of privilege and oppression. These groups may combine ethnoreligious subcategories and racial identities in a number of ways; however, almost all of them strive to be read as not Arab. Non-Arab, non-Muslim, non-Jewish peoples with a long history in Israel, such as Armenian Christians, are marginalized civically and politically , and do not figure largely in the racial imaginations of most Israelis. Newer non-Jewish, non-Arab immigrants have also been drawn to modern Israel, including a population of Catholic Latin Americans. They too are a very small minority and are generally excluded from discussions of racial formation and hierarchy within the country. Considering these elisions, the most basic division of Israeli society is thus between Jews of any race or ethnicity and Palestinians. Israel’s situation is quite different from American racial projects, which are perhaps its closest cousins, and I do not wish to ignore these differences or apply American racial optics carelessly. Israel’s history, its theological governance, and its demographics are very different, as are its modes of thinking about race, citizenship, and belonging. That being said, some models of race developed in the United States, when adapted, can shed light on other cases. In Israel specifically,stackable flower pots bringing in such theories is useful because countries wrestle with a popularly assumed racial binary that hides much diversity. When used alongside scholarship like that of Sasson-Levy and Shenhav, the existence of the imagined but strict Israeli/Palestinian binary leads to fruitful theoretical comparisons. In particular, I find that this system in some ways resembles Claire Jean Kim’s U.S.-based theory of racial triangulation. 

Kim theorizes the racialization of Asian-Americans within the American “field of racial positions” as a process that does not happen in a vacuum in which each ethnoracial group receives particular treatment independent of the treatment of other groups, nor in a strict hierarchy bounded by Black and White, but “relative to and through interaction with” all groups. These fields of racial positions acknowledge the power of public discourse, personal interactions, and structural forces in shaping the relative privilege of racial groups in a shifting arena specific to time and place. This form of racialization allows for multiple axes of racial formation and foregrounds the manner in which different groups are racialized through comparisons with others. When she argues that Asian-Americans are “racially triangulated” within these fields, she illuminates the ways in which Asian-Americans define themselves and are defined by others in contrast to White and Black Americans through processes of relative valorization and social ostracism. By borrowing Kim’s vocabulary to refer to Israel, I locate Iquiteño-Jewish migrants within a field of racial positions that includes Palestinians, non-Jewish and non-Arab migrants, and multiple subgroups of Jews with varying levels of ethnic and religious privilege. Their identity is triangulated in relation to, especially, light-skinned Ashkenazi Jewish Israelis and Palestinians. Iquiteño Jews, mostly, are converts in the Conservative/Masorti movement, people with dark skin, people with Sephardi rather than Ashkenazi heritage, second- or third-language speakers of Hebrew, and recent migrants. As such, they are racially constructed through social ostracism when compared to light-skinned Jewish Israelis, European-descended Ashkenazim, first-language speakers of Hebrew, those born in Israel, and Orthodox Jews, among other axes of identity. Legally, as non-Orthodox Jews, they have fewer dejure rights in Israel, such as to marriage. Socially, they face colorism, language discrimination, anti-immigrant bias, and anti convert bias. At the same time, they enjoy innumerably more rights, both de facto and de jure, than Israel’s Palestinian citizens. How aware of this situation are the Jews of Iquitos? It is not clear to me or to my subjects how legible Iquiteños moving through Israel are as non-Arab, or even perhaps non-Christian. However, it is clear that in Iquitos, potential olim know enough about Israeli racial hierarchies to name themselves as emphatically not Palestinian, and to preemptively take action to distance themselves from Palestinians. Interview subjects did so by expressing their desire to move quickly away from Ramla, which they saw as a demeaning or undesirable place to live because it had a high proportion of Arab residents. A younger female friend of S, the interviewee who opened this chapter, told me in hushed tones that she had heard Ramla was violent and unhealthy —because of its Arab population. My youngest respondent, a young man of , planned to immediately join the IDF for a variety of reasons, including the opportunity to undergo an expedited Orthodox conversion in the military, but also to “defend [Israel] from rats,” meaning displaced Palestinian families who might wish to return to their ancestral homes. My hosts appeared generally moderate in their Peruvian political opinions, and were by and large vehemently anti-Trump, but when I asked them who they would vote for in the then-upcoming Israeli prime ministerial election, they responded that they liked and approved of the Likud party’s policies around checkpoints and the building of new settlements.

Clearly, many Iquiteño Jews felt a deep anxiety about Palestinians in Israel. Those who did not involve themselves politically were nonetheless entering a situation in which their presence would inherently help the Israeli state disenfranchise Palestinians with equanimity. At the same time, my respondents divulged much less anxiety to me about their position within the intra-Jewish Israeli hierarchy. Although in 2019, three individuals informed me that Ramla was undesirable not only because of the large Arab population but also because they felt other Latin American Jews were broadly undesirable to be identified with, few others expressed such sentiments. While many told me they felt anxious about learning and using Hebrew on a daily basis, introducing their children to such a new place, or finding good work, it seemed to me that most felt excited about merging into a Jewish-Israeli whole, deeming such assimilation entirely possible. It was not clear to me in any instance in my 2019 interviews that individuals felt they “should” be more identified with either Ashkenazi or Sephardi Jews in Israel, or that there was much trouble with racism within the Jewish population in Israel. Some older respondents, particularly when I spoke to community elders whose families had maintained Judaism through the Iquitos community’s lean years in the late 20th century, mentioned that they strongly identified as Loretano Jews, who had a practice and history all their own, but that identification waned quickly as respondents grew younger. Those who felt those ties to a Peruvian, non Ashkenazi form of Jewishness were also much less likely to report a desire to migrate or a sense of already being Israeli, rather than or in addition to being Peruvian. This provides a picture of Jews who feel themselves already comfortably ensconced within a privileged majority. That said, I do find it interesting and important that even three of my respondents would feel the need to preemptively distance themselves from other Jewish Latin Americans living in Israel. It is even more interesting that not a single person I spoke to was interested in reclaiming the traditions of their Moroccan-Jewish ancestors, or connecting with Moroccan-Jewish communities within Israel. The current community leaders had not considered reaching out to the Sephardi Chief Rabbinate for assistance or educational materials, content with the Ashkenazi-normative materials and training sent by such organizations as the Jewish Agency for Israel. However roundabout the way, and however quiet the transmission, clearly some Iquiteños are receiving some information that allows them to preemptively triangulate themselves before making aliya. Information that comes to Iquitos about racialization in Israel comes from Iquiteño Jewish family members and friends living in Israel, the Spanish-language Jewish news media, rare features in the general Peruvian press dealing with Israeli issues, Jewish organizations interacting directly with Iquiteños, and visitors. Notably, most of the Iquiteño Jews could not name a favored Israeli party or politician when I asked them to. 

In the case of Iquitos, why do people simply not respond to Mormon or Evangelical Christian overtures? The community, its actions, and the relationships converts build with each other are key not only to why individuals convert, but can explain how new converts are brought into the fold. In the field of pastoral psychology, Ines Jindra combines two important concepts in the service of studying conversion: critical realism and the toolkit approach8. Critical realism allows for multiple levels of truth, which Jindra characterizes as what really happened and what actually happened. This allows personal conversion narratives to be important and truthful while also acknowledging other forces that may push someone towards conversion. It goes some way to healing the problem Gauri Viswanathan sees in the sociological study of conversion, where personal narrative and the power of belief are disregarded. The toolkit approach, meanwhile, draws on cultural studies to recast religion as a tool with many uses, both spiritual and practical. In this way, granting religion validity as a tool means that transformation, where there is a change in a person’s values, outlook, and sense of self, among other key characteristics, and conversion, a change from one religion to another, do not march in lockstep. Yang and Abel, while they intend to characterize the sub-field of sociology that focuses on conversion, also lay out a three-tiered model from which they say sociologists pick and choose influences. I intend to use this model more intentionally, where the tiers are like baskets from which certain influences are more salient, and which the convert responds to with their religion, as in toolkit theory. The three levels, or baskets, are the macro,aeroponic tower garden system the meso, and the micro level. The macro has to do with very broad-scale forces, such as globalization or transnationalism, that change a person’s societal surroundings.

This could connect to Lofland and Stark’s predisposing conditions. The meso could also be called the institutional level; it is where congregations, community and activist organizations, and even large international NGOs are found. This level is critical to the supply side Phillips and Snow identify; these are the institutions that shape what affective bonds and intensive interaction can look like for a particular community. Finally, the micro level is where individual narratives of spiritual seeking, feelings of belonging, or personal troubles can shape decisions to convert. I have chosen not to copy these levels exactly but to adapt them, combining the individual and the immediate religious community, seeing the international arena of individual states as the middle level, and taking in the grand networks of transnational activity as the largest scale. In understanding conversion in Iquitos, then, I draw from each of these models. In particular, the focus on community, the recognition that religious communities are affected by strong political forces, and the connection between the individual and the world are key. Drawing from Yang and Abel’s leveling technique, the various factors can be described as follows. At the global level, individuals a macroeconomic and political situation that makes migration from Peru to Israel more attractive in general, and a transnational social field made possible by global advances in transport and communications technology. The Iquitos case is interesting on itsmerits, and it also helps us understand that the usual sociological division between practical and religious motivations for conversion is flawed, and that any focus on conversion as purely instrumentalist or purely a subject for the spirit is necessarily incomplete. It is obvious that religion and worldly concerns influence each other, but when it comes to conversion, sometimes worldly concerns are religious and vice-versa.

Furthermore, Iquitos helps us understand how narratives and myths of diaspora can actively drive practical transnational movement in the modern age by creating new forms of religious authenticity linked to politics, place, and movement. At the state level, major Jewish institutions like the Jewish Agency operating in Latin America are interested in potentially supporting an isolated community with a complex history are primarily Ashkenazi, usually quite large, and often connected with the State of Israel. In Israel, the Law of Return’s current iteration requires certain bonafides from potential immigrants. Together, these forces have helped shaped what conversion, and therefore Jewishness, looks like in Iquitos. Finally, at the individual/community level, individual Iquiteños interpret and respond to the institutions and options available to them using all the tools in their kit, including religious ones, which are in turn influenced by the two broader levels. By the end of this chapter, I wish to demonstrate that the Latin American-Jewish institutional resources available to the Iquitos community early on shaped an orientation towards Israel. That early orientation combined with the economic situation of Iquitos led to an early wave of migration. Those first migrants established what would become a transnational social field between Israel and Iquitos. The template for Jewish education and conversion continued combined with contact between Iquiteños in Israel and Peru led to a blending of Jewishness and Israeliness in the Iquiteño imagination and also provided more standard pull factors for further migration, resulting in state appropriation of diasporic identity to drive today’s migration patterns.Traces of Iquitos’ historical Jewish presence jump out from between the saints’-name streets, the churches and monasteries, and Jesus-bedecked public buses with surprising ease. The large supermarket in the historic city center does business in the old Casa Cohen, its sign still hanging above the portales that give the current store its name. On the same street is the current synagogue,dutch bucket for sale hidden behind a mattress and fabric shop.

One of the ubiquitous mototaxis coughs by with a phone number and an elaborately calligraphed surname that immediately surprises me with its almost humorous Jewishness — I later hear from an interview subject who shares the same apellido that the owner-driver is a distant cousin from the branch of the family that did not hold onto or return to their Jewish ancestry. Iquitos’ most famous living artist is the ironically named Christian Bendayán, descendant of second-generation patriarch León Bendayán. In the municipal cemetery, a small fenced-in meadow marks the Jewish section, where flowers give way to river pebbles and red-and-black huayruro seeds placed on the headstones. Someone was buried there just two months before I arrived. Online, things look pretty good too. The Kehilá runs not one but two Facebook pages which post at least a few times a week, and the first Google search result for “Iquitos synagogue” is a helpful webpage on TurismoJudaico.com. At the time of writing, the English-language Wikipedia page returns nine results for the word “Jew,” the Spanish page five, while on Hebrew Wikipedia, the section simply called “Yehudim” is more than twice as long as the general history section. Several articles in online newspapers also come up in a Google search, from long features in The New York Times and The Guardian to Sefardi special-interest websites to Zionist RSS feeds to local Spanish-language dailies. Most of them have been written since 2010, when The Fire Within, a 2008 documentary directed by Lorry Salcedo Mitrani about the community’s renaissance, made the film festival circuit. All this despite the fact that the most common response to my research wherever I go is an incredulous, “There are Jews in Peru?” Sitting in the courtyard of the synagogue, conducting my scheduled interviews and also swooping down on unsuspecting visitors who drop by for coffee, help with Israeli immigration documents, and sometimes mattresses, I get a different picture. A little girl of six who I remember as a toddler from my last visit tells me in passing that she always comes to Monday “Judaism classes” because it is a chance to see her same-age friends, who, she sighs, will all be leaving soon except for her. Of all my interview subjects in 2019, only that girl’s father and two others tell me they intend to stay in Iquitos with their families to keep the Abramowitzes company. Over coffee on day one of my 2019 visit, Jorge Abramovitz, the de facto leader of the community and owner of the synagogue building, tells me something Ryan Schuessler quoted him on in The Guardian in 20169: “La comunidad puede morir.” The community may die. The sentiment is independently repeated to me by Señor Abramowitz’s wife, several of my interview subjects, and the little girl, who appoints herself my unofficial guide after I spend at least an hour with her lying on our fronts trying to make nice with the mattress shop’s resident ice queen cat. The presidents expect that no more than five to seven families of the twenty or so presently there will remain — some will have to stay whether they want to or not due to family matters or money troubles.

What can explain the gap between the international perspective on Iquitos and the reality that the community once more appears to be going dormant, if not dying?Migration is an intrinsic part of broader processes of development, social transformation, inequality, and globalization. The relation between migration and inequality is complex and fundamentally non-linear, but there is a strong relationship between economic development and migration. It is generally assumed that when moderately high inequality and an international arena that encourages some movement exist in conjunction, an integrated migration system exists. As of 2018, Peru’s GNI per capita was 6,530 USD, while Israel’s was 40,850 USD, a clear difference, although as of 2016, both countries’ GINI index score was only 4.6 measures apart. Generally, middle-income countries like Peru have the highest emigration rates because of a combination of relative deprivation and tighter links to developed countries — in Iquitos, this link is the somewhat nonstandard link between Israel and the global Jewish diaspora.Israel, despite a sometimes difficult relationship with its diaspora , has for decades engaged in aggressive outreach to Jewish populations across the world. This includes legal provisions such as the Law of Return, which guarantees access to Israeli citizenship for migrants who meet state-determined baseline criteria of Jewish practice and/or ancestry. Accessing the benefits of this law often requires that potential migrants be able to provide documents such as parents’ Jewish marriage certificate , burial records, and/or documentation proving conversion. Since the 1970s, the Israeli state has in general encouraged both migration and conversion in order to boost the absolute numbers of Jews in the country, although this has deepened struggles between secular Zionists and ultra Orthodox religious Jews in the state apparatus, and led to ambiguous or difficult situations when groups cannot provide such documentation, claim Jewish identity, and do not convert. NGOs like the Jewish Agency for Israel and the Jewish National Fund conduct outreach between Israel and other countries, while organizations at the national level, like the Federación Sionista del Perú, engage in Israel-positive activities for a local or regional audience. Conceiving of Israel as the natural center of Jewish life, practical or religious, is a relatively recent phenomenon: indeed, for most of Rabbinic Jewish history, the land that was to become Israel was a backwater that maintained a symbolic, ritual importance rather than being a practical goal for most Jews. As will be discussed in the next chapter, that the modern state of Israel today seems a natural point of interest for Jewish migrants across the globe is evidence of a successful parlaying of a symbolic diaspora, which was in reality only loosely connected between its individual nodes, into practical transnational activity, including migration, money flow, and idea exchange. Altogether, it seems evident that migration was a response to circumstances that any Iquiteño person might have chosen. This simple model does not explain, however, why Israel? Why not Lima, the center of Jewish life within Peru? Beyond internal migration, why not the U.S., Spain, or Argentina, the first, second, and third most-common host countries for migrant Peruvians ? Why go through the long and involved process of conversion , followed by the long and involved process of making aliyah? It is the history of the state and institutional history one level down from the interconnected world that helped fuse Jewish and Israeli identities in Iquitos that explains why Israel specifically became the goal.

That P. ramorum also persisted on green leaves at high levels for the entire 16 weeks despite the loss of approximately 40% of leaf biomass stands in contrast to our previous findings where its colonization of leaves peaked within a few weeks after exposure in natural streams, but then rapidly dropped to very low levels as colonization by clade 6 Phytophthora species rose and persisted at high levels. This is evidence that the reduced recovery of P. ramorum from green leaves in natural streams as decomposition progressed was due to displacement from saprotrophic organisms like clade 6 Phytophthora species. Unfortunately, P. ramorum was completely suppressed from colonizing leaves in combined inoculations with P. gonapodyides and it could not be determined if the pattern observed in field experiments would occur under these simulations when both species were present. The suppression of P. ramorum colonization of green leaves in combined Phytophthora inoculations—consistent across all three experiments—was surprising because both species were effective at colonizing leaves when inoculated alone. One explanation could be that sporulation of P. gonapodyides from mycelial mats occurred earlier than that of P. ramorum and that the latter was therefore precluded from leaves because in all experiments, full colonization of green leaves by P. gonapodyides occurred very rapidly. Indeed, in the first experiment, colonization of P. gonapodyides occurred more rapidly on green leaves than that of P. ramorum. However, baiting two days after inoculation in the second experiment showed that P. ramorum spores wereactive in the microcosms where it was inoculated alone,dutch bucket hydroponic but almost absent in the combined inoculation microcosms. This suggests that the presence of P. gonapodyides itself may have suppressed sporulation by P. ramorum. The rapid leaf colonization by P. gonapodyides in these microcosms also contrasts with the slower colonization that was observed in natural streams and may be an artifact of high inoculum loads and the relative abundance of substrate.

The aim of these experiments was to characterize the capacity of each organism for growing and reproducing from each type of leaf rather than estimating typical colonization and decomposition in streams. Though logistically more difficult to prepare and standardize for an experiment of this magnitude, using sporangia or zoospore inoculum rather than mycelial mats may overcome the problem of uneven inoculum activation, the success of which we have experienced in smaller scale experiments. Alternatively, the use of colonized plant tissue instead of mycelial mats as a source of inoculum may also produce a different outcome from the suppression of P. ramorum that we found with this approach in mixed inoculations. Interestingly, the kind of succession observed in field experiments did occur in a few control microcosms into which both Phytophthora species were accidentally contaminated. However, the limited occurrence and unknown relative quantity of original inoculum precluded more substantial evaluation. In any case, the suppression of P. ramorum sporulation in treatments where P. gonapodyides was present raises the question of what mechanism was responsible for the effect. It also furthers the impression that P. gonapodyides and other clade 6 Phytophthora species may have a moderating effect on the presence of P. ramorum in streams. The green leaves that we used were of mature cuticle and collected in midwinter and late summer for the first and second experiments, respectively. While some seasonal variation in susceptibility to P. ramorum infection has been reported in California bay leaves, the physical and chemical properties of mature leaves have also been reported to be relatively consistent throughout the year. Our results were similar for both experiments, and therefore, any variation in the leaves was overcome by experiment factors. The extensive colonization of brown leaves by P. gonapodyides and their limited colonization by P. ramorum is consistent with previous work where we showed that the former is a competent saprotroph while the latter is relatively ineffective at colonizing dead tissue. A significant discovery in this work was that P. ramorum colonized yellow, senescent leaves that were still fresh and had an intact cuticle to nearly the same degree as it did green leaves.

At this stage, though chloroplasts and most of the protein content are gone from leaves, the cells are expected to be still alive, while in brown leaves that have dried the cells are no longer biologically active. In fact, colonization of the yellow leaves by P. ramorum was not quite as extensive as its colonization of green leaves in the second experiment, which ran more or less concurrently and in which green and brown leaves were maintained in separate microcosms , though the difference between the separate experiments was not analyzed statistically. Though green leaves are shed into streams as a relatively low proportion of total litter, yellow leaves, often shed directly into streams from trees, constitute a much greater proportion of leaf litter in streams. This indicates that a great proportion of leaf litter in the streams is suitable for colonization by P. ramorum, and conforms to the regular recovery of this pathogen from natural leaf litter. Furthermore, the degree of colonization of yellow leaves by both Phytophthora species remained persistent throughout the 16 weeks, as with green leaves in the other experiments, suggesting that the same kind of succession may be expected in these leaves as seen with green leaves in natural streams. Also consistent with previous findings with leaves colonized in naturally infested streams, leaves colonized by both Phytophthora species were generally conducive to sporulation as detected by baiting from the microcosms. Phytophthora gonapodyides was consistently recovered from P. gonapodyides-only and combined Phytophthora species inoculation treatments where it had colonized all green and brown leaves at all sampling points. The results from baiting of P. ramorum spores from microcosms were less regular, but nonetheless, mostly successful from microcosms containing colonized green or yellow leaves and occurred minimally from microcosms containing brown leaves which were colonized at only very low levels. The relatively less frequent recovery of P. ramorum by baiting from microcosms with non-sterilized stream water, not observed for P. gonapodyides,dutch buckets system may be the consequence of P. ramorum not being well adapted to sporulation in biologically active aquatic environments or relying on different environmental signals.

Nevertheless, these results confirm that both of these Phytophthora species can sporulate from colonized, decomposing leaves, whether green, yellow or brown leaves. Furthermore, at least under these conditions, their spores persisted for weeks and even months after any visible substrate was available, though the effect occurred more defifinitively and for longer with P. gonapodyides. As P. gonapodyides is not known to produce long-term survival structures, the question arises of how P. gonapodyides persisted so long in the microcosms in the absence of leaves. This observation also stands in contrast to our successful elimination of Phytophthora spores from original stream water collections simply by holding the water at cool temperatures for approximately three weeks. The observed persistence of spores of both Phytophthora species may be the result of an abundance of zoospore cysts due to the compact nature of the microcosms, or perhaps because the spores originated from propagules that would not have been suspended in the water column of the flowing streams. While oomycetes have been acknowledged as decomposers in aquatic environments until recently they have primarily been regarded as acting on non-cellulosic detritus such as insect and animal tissue. As most Phytophthora species are known as plant pathogens, the recent evidence that they may also degrade plant tissue in detritus is not surprising. Parasitism is considered an early characteristic in the evolution of oomycetes, but the possible evolution of a saprotrophic lifestyle from parasitic precursors has been considered for fungi and oomycetes.Stradling saprotrophic and parasitic lifestyles, stream-resident Phytophthora may play an important role in the early breakdown of leaves and vegetative matter that still contain living cells. As facultative pathogens, clade 6 Phytophthora species can enter living cells and open intact tissues to further colonization by other saprotrophic organisms with less ability to penetrate living tissue. This is analogous to the paradigm of ‘conditioning’ of vegetative litter by pioneer microbial species, though in this case with respect to secondary saprotrophic microorganisms that could not on their own overcome physical and chemical protections still present in senescent but still alive leaf tissue. Our results were consistent with this hypothesis, as green leaves decayed more slowly in the absence of Phytophthora. It is uncertain why in the first experiment green leaves in the treatments with no Phytophthora inoculation decomposed very little over the entire 16 weeks of the experiment. In this experiment, both green and brown leaves were maintained together in microcosms, and it is possible that leachate from the leaves, particularly the brown leaves, may have had an inhibitory effect on some microorganisms. In the second experiment, leaves were leached prior to being deployed in the experiment, and also green and brown leaves were kept in separate microcosms. Green leaves in non-inoculated controls in the second experiment lost biomass to a degree ultimately similar to that of inoculated treatments, albeit at a slower rate. This indicates that other organisms were present that could initiate the decomposition of green leaves through the presence of Phytophthora accelerated it.

We attempted additional isolations from some samples of leaves on acidified potato dextrose agar medium and found that the leaves in both controls and inoculated treatments were generally well colonized by a multitude of fungi. The fact that similar fungi occurred on leaves from microcosms prepared with both sterile and non-sterilized stream water suggests that many of these fungi were present on the leaves before entering streams as leaf litter.Additionally, overall there were no differences in decomposition rates between treatments with sterile or non-sterilized stream water added. Decomposition was also similar for leaves colonized by either Phytophthora species, indicating that, though P. gonapodyides is a better adapted saprotroph, both species had a similar effect on the decomposition of live, green and yellow leaves. This would be consistent with Phytophthora having the effect of opening integral tissue to colonization by other saprotrophs that then push decomposition forward. Finally, it is interesting that the presence of fungi in these leaves did not affect the persistence of P. ramorum throughout the experiments, suggesting that they are using different resources and that the successive displacement of P. ramorum in previous work may be specific to competition with other Phytophthora species or similar organisms. Under natural conditions, leaves would be exposed to a greater diversity of organisms, including other oomycetes such as Phytopythium species. As P. gonapodyides can colonize dead leaf tissue, it could be expected that it would contribute to leaf decay in brown leaves as well. This was not observed, as loss of biomass in brown leaves was the same in all treatments unaffected by Phytophthora colonization. The fact that P. gonapodyides substantially colonized brown, senesced leaves, but did not increase the rate of biomass loss raises the question as to what resources the organism uses in this substrate. Though biomass loss is a useful measure of decomposition, it does not offer a complete picture and other measures, such as changes in leaf toughness or chemical properties may offer a fuller picture of decomposition that could account for the effects of Phytophthora colonization. Moreover, decomposition of brown leaves proceeded more slowly in the second experiment than the first. This may be due to lower nitrogen and other nutrient availability both because in the first experiment green and brown leaves were maintained together in microcosms and also that in the second experiment, the leaves were leached prior to being introduced into microcosms at the start of the experiment. This may also be the reason that colonization of brown leaves by P. gonapodyides was significantly less than that of green leaves when leaves were kept in separate microcosms, while the levels were similar when leaves were maintained in the same microcosms. Another possibility is that sporulation from green leaves allowed greater colonization of brown leaves where the leaves were kept in the same microcosm. Our results demonstrate that green and yellow California bay leaves are suitable substrates for the growth, colonization, and sporulation of P. ramorum in streams where they constitute a significant proportion of vegetative litter, they likely play an important part of supporting the inoculum load in streams.

However, degradation product concentrations and detection frequencies were lower in the present study, likely attributable to the fact that samples were collected from homes treated with a single application of fipronil. Together, results from this and other studies indicated that dust particles exposed to fipronil may retain fipronil and its degradation products for many months after application. This suggests that urban dust may serve as a source of fiproles, especially fipronil and fipronil desulfinyl, in urban runoff long after the conclusion of pest treatment activity, barring removal or offsite transport of the dust prior to the occurrence of a runoff event. Fipronil sulfone levels gradually increased from 1 d to 153 d, with mean concentrations ranging from 1.43-209 ng g-1. Fipronil has an aerobic soil half-life of 188 d , which supports the finding that mean fipronil concentrations were similar over the 153 d period considered in this study. In addition, the gradual formation and increasing soil concentrations of fipronil degradates was consistent with the relatively slow degradation rate of the parent compound. Fipronil and fipronil sulfone were detected with the greatest frequency and at the highest maximum concentrations. Fipronil desulfinyl and fipronil sulfide were detected less frequently and at substantially lower maximum concentrations. Fiproles were measured in soil samples at detection frequencies similar to those measured in dust , but maximum soil concentrations were much lower than maximum dust concentrations. It is possible that soil concentrations were low relative to dust concentrations because soil samples were collected to a depth while dust particles partially originated from wind erosion of the surficial soil. Fiproles have been shown to be enriched in fine particles characteristic of urban dust ,ebb and flow trays suggesting that residues initially present in the surrounding soil may have contributed to contamination of loose dust particles on impervious surfaces.

Results summarized herein reveal that soil treated with fipronil-based pesticide formulations remains contaminated by fiproles for a significant amount of time following treatment and is a source of fipronil degradation products. These data collectively imply that soil has the potential to contribute fipronil and its degradation products to their loads in urban runoff. However, this contribution likely depends upon the entrance of soil particles into runoff, either by inundation of soil with a large runoff volume after a prolonged rainfall, an irrigation event, or by prior transport of soil particles onto urban impervious surfaces. Mean concrete concentrations of fiproles were at their highest 1 d after application and decreased subsequently by 57-89% at the 30 d sampling point. Fipronil was rapidly transformed after application such that its degradation products were detected at high mean concentrations 1 d after application. This finding was consistent with results of a recent study focused on the degradation of pesticides on urban hard surfaces, where it was observed that fipronil was rapidly transformed to its biologically active degradation products on concrete in bench and field experiments. Mean concentrations then remained relatively stable for the duration of the sampling campaign, with 30 d concentrations being similar to those at 79 d, 110 d, and 153 d. Detection frequencies of fiproles in concrete ranged from 27 to 92%, with maximum concentrations of 3.19-25.4 µg m-2.The most prevalent degradation product was fipronil sulfone , while fipronil desulfinyl was detected at a higher maximum concentration than the other degradates, second only to the parent compound. An investigation of the contribution of fine particles to the runoff loads of pyrethroid pesticides also revealed high concentrations of bifenthrin and permethrin on concrete following application of professional pesticide formulations. Concrete data further showed that fiproles were present in the concrete at detectable concentrations for several months after initial application of fipronil for pest treatment. This suggests that concrete may act as a long-term source of these compounds in urban runoff.

Several linear regression analyses were performed to assess the presence of statistically significant linear relationships between fiprole concentrations in different urban solid matrices and concentrations in runoff water.A statistically significant relationship would indicate that a given component may be an important source for fiproles in runoff. It was observed that statistically significant relationships existed between the runoff and concrete concentrations of fipronil desulfinyl, fipronil sulfide, fipronil, and fipronil sulfone. A previous study similarly uncovered a highly significant linear relationship between runoff concentrations of pyrethroids and their concentrations on concrete surfaces measured using a surface wipe method. In this study, significant relationships were also found between the runoff and dust concentrations of fipronil desulfinyl and fipronil. Recent studies have also implicated dust particles in the offsite transport of hydrophobic organic contaminants, but the present study was the first to directly evaluate the connection between dust and runoff loads of fiproles. The significance of the concrete-runoff and dust-runoff relationships for fiproles together suggested that dust on impervious urban surfaces and residues on concrete are important sources of fiproles in runoff. Statistical analysis, however, did not show soil as a significant source for fiproles in runoff water. As discussed above, even though soil was not a direct source, it is possible that soil particles in the surface layer may be transported via wind and other mechanisms onto impervious surfaces, indirectly contributing to the contamination of runoff water by fiproles. Soil particles likely represent a major component of urban dust; other components may include concrete fragments generated from weathering and plant debris. Taken together, the most important finding of this analysis was that the effectiveness of mitigation efforts would be improved by focusing on reduction of dust particles on impervious surfaces and prevention of pesticide contact with concrete surfaces such as driveways. Moreover, the established regression equations may be used to predict fiprole loads in runoff using levels in urban dust and residues on impervious surfaces, before a runoff event occurs.

Contamination of surface water by fiproles poses a threat to many benthic invertebrate species. Fiproles may therefore exert a significant effect on the benthic community structures of urban streams.However, even though runoff from a given residential area enters downstream surface water as a point source,4×8 flood tray surface runoff from individual homes in a neighborhood resemble nonpoint sources and is technically challenging to control. Identification of concrete surfaces and urban dust as the major sources of fiprole contamination of surface runoff at the site of pesticide treatment highlights their importance in the effort to reduce fiprole residues around a homesite, especially on impervious surfaces. The combination of rampant urbanization, rapid population growth, and global climate change has resulted in an extraordinary reduction in the potable and non-potable water supply worldwide. The deficiency of clean water supplies has led several nations, including the United States, to encourage a reduction in water use and pursue a myriad of water treatment and recycling initiatives. Water scarcity is exacerbated by pollution of surface water and ground water resources by anthropogenic contaminants such as pesticides. Indoor and outdoor use of insecticides in urban areas has been shown to cause contamination of urban surface water sources. Urban-use insecticides are incompletely removed at wastewater treatment plants before the release of effluent into surface streams, and runoff after rain and irrigation events further exacerbates surface water contamination. Fipronil and the synthetic pyrethroids are insecticides utilized at high rates in urban environments for professional and homeowner control of structural pest species such as ants, termites, spiders, and roaches, as well as for elimination of fleas and ticks in veterinary medications. Fipronil and its primary degradation products, fipronil desulfinyl, fipronil sulfide, and fipronil sulfone are moderately hydrophobic compounds while the pyrethroids are highly hydrophobic with log Kow =5.7-7.6. Numerous studies have shown occurrence of both insecticide classes in urban surface water at toxicologically relevant concentrations as well as in the sediment where residues may persist long after deposition. Furthermore, fipronil’s major degradation products exhibit toxicity equal to or greater than that of the parent compound. There is also evidence of additive pyrethroid toxicity in sensitive organisms. Fiproles and pyrethroids are easily transported in surface runoff and are present in WWTP effluents , aggravating the risk of toxicity to non-target aquatic species. In arid or semi-arid regions such as California, some urban streams are predominantly fed with urban runoff drainage and WWTP effluents.

Constructed wetlands are one potential solution to the shortcomings of WWTPs and the general lack of storm water treatment. They have been shown to remove nitrogen and phosphorous species, metals, antibiotic resistance genes, and various organic compounds. Existing data suggest that CWs are effective in reducing concentrations of fiproles and pyrethroids. However, field data on the performance of urban wetlands are limited, and in-depth information on the role of various wetland compartments is scarce. In this study, samples were collected from the Prado Wetlands, a 182 ha constructed treatment wetland system located in Southern California containing open water and vegetated cells, from June 2018-January 2019 and analyzed for fiproles and pyrethroids. The primary objectives were to determine the removal of these trace contaminants by the surface flow wetland, to understand the underlying processes most responsible for contaminant removal, and to estimate potential alleviations in invertebrate toxicity. It was hypothesized that sediment sorption and biodegradation would play a major role in the removal of fiproles and pyrethroids, resulting in reduced aquatic toxicity. Results from this study may be used to optimize the design of CWs and related water treatment systems to improve the quality of recycled water and to attenuate ecotoxicological and human health risks from potable and non-potable applications.Fipronil , fipronil desulfinyl , fipronil sulfide , and fipronil sulfone were obtained from the United States Environmental Protection Agency’s National Pesticide Standard Repository. Bifenthrin and deuterated bifenthrin were purchased from Toronto Research Chemicals. Cyfluthrin was purchased from Santa Cruz Biotechnology. Ethiprole was obtained from the Shanghai Pesticide Research Institute. Decachlorobiphenyl was purchased from AccuStandard.Solvents and other chemicals used were of pesticide or GC-MS grade. This study was undertaken at the Prado Wetlands in Corona, CA. This 182 ha complex of 45 surface flow wetland ponds was constructed in the 1990s and was initially established to remove NO3 – from the Santa Ana River. Up to 50% of the Santa Ana River flow, which consists primarily of treated wastewater during non-storm seasons, is diverted into the wetland system for treatment. Additional details regarding the Prado Wetlands are provided in the Supporting Information. The ponds selected for use in this study were cells S5 and S6 , which together constitute a 4.45 ha vegetated CW complete with inlet and outlet weir boxes. In the context of this study, this vegetated CW will be referred to as the Prado Constructed Wetland. The hydraulic retention time of the PCW was estimated to be 1.29 d based on the results of a pilot-scale rhodamine WT tracer experiment conducted at the Prado Wetlands. Samples and measurements were taken at the inlet weir box , the interface between ponds S5 and S6 following the connection pipe , and the outlet weir box. Water, sediment, and plant samples were collected from the PCW monthly during the period of June 2018-January 2019, with the exception of September 2018 when there were ongoing maintenance activities. Triplicate 1 L water samples were collected in amber glass bottles at the inlet, midpoint, and outlet of the PCW. Inlet and outlet samples were collected from the water flowing into the corresponding weir boxes, while midpoint samples were collected by placing bottles below the surface of the water against the direction of flow. Sample bottles were transported to the laboratory on ice and stored at 4 °C until extraction. Before extraction, water samples were passed through 0.7 µm filters to separate the TSS from the water. Filtered TSS samples were then dried in preparation for extraction. Wetland water samples were extracted using a method in Gan et al. , with modifications. Briefly, 30 mL of NaCl was combined with each water sample and liquid liquid extraction was performed with 60 mL aliquots of dichloromethane. Each extract was drained through a funnel containing anhydrous Na2SO4 to remove residual water, evaporated with a Büchi RE121 Rotovapor , and solvent exchanged into 9:1 hexane:acetone. Samples were then evaporated to approximately 0.5 mL under a gentle nitrogen stream and reconstituted in 1.0 mL hexane for analysis.

It is interesting to note that the region is actually quite weak in environmental and conservation employment, despite the presence of strong water policy nonprofits. This is largely due to the majority of the State’s environmental organizations being headquartered in the Bay area, or in the state capital, Sacramento. These organizations, such as the aforementioned influential Pacific Institute, are very active in Southern California water policy. The Pacific Institute is a global water policy research center producing reports an all matters of water and issuing a yearly report, The World’s Water, which comprehensively documents the state of the world’s water. Dr. Peter Glieck is an international water policy celebrity who lectures throughout the world. Despite having less environmental organizations then the San Francisco bay, Southern California does have some very important environmental organizations. For example, Heal the Bay and Surfrider have been extremely successful in educating the public and government agencies about storm water pollution into the Ocean. Southern California does not receive very much rain, a little over 17 inches a year, but thanks to the extensive flood control infrastructure—most obviously the concrete drainage tunnel that was formally the Los Angeles River—the majority of rain it does receive is quickly flushed into the ocean—usually within 24 hours . In addition to education and pushing the policy debate, organizations like Heal the Bay, Tree people, Surfrider, The Council for Watershed Health are helping to bring about so-called soft path approaches to integrated water management. Surfrider for example, runs a very successful ocean friendly garden landscaping program which promotes on-site water storage, . Tree people has been at the forefront in developing studies—including a pioneering study on the value of urban trees —and promoting low impact development in the Los Angeles region. The Council for Watershed Health not only conducts research but also builds model low impact development urban designs that promote water conservation.

These organizations are working to build support for local integrated water management techniques but they have a long way to go. These organizations also work actively with firms and industrial networks in order to serve to further promote knowledge diffusion. All nonprofit organizations by definition do not generate profits,flood table or if they do the must reinvest their profits into operations. These entities are organized under the IRS 501 tax code and pay less, or in the case of 5013 organizations, pay zero Federal taxes However, 5013 organizations are extremely limited in the activities that they undergo. First, they can not make a profit that benefits share holders or a private entity. Second, they are limited in their ability to influence legislation may not participate in any campaign activity for or against political candidates . However, in practice, the ban against political campaigning is very narrowly defined, and nonprofits are free to dedicate themselves to working on behalf of a cause which may have political ramifications. It is very notable that in contrast to these case studies, there are very few organizations dedicated to building the water industry for economic reasons. There is no “Californian water sector” like there is a “Dutch water sector” nor is there a true equivalent to the Singapore Water Association or a Milwaukee Water Council. In fact, on the Sectary of State’s web page listing California’s trade associations, not one mentions water . The important networking and knowledge diffusion functions are often filled by existing industry trade associations, various water agencies—most importantly MWD, LADWP, and OCWD—or universities such as the ones highlighted in Chapter 4.5, Knowledge Creation. Despite numerous entities marketing the region’s water expertise, there are not very many independent organizations focused on trumpeting the regional water industry as a jobs creation tool. Although to be fair, California is one of most well known brands in the world.

Thanks to Hollywood’s movies, much of the world might have an inkling that we have water problems—anybody who has watched one of the numerous car chases filmed in the Los Angeles River could probably venture a good guess. Still, the lack of a regional economic water industry message is somewhat surprising, and even the general regional trade associations like Foreign Trade Association of Southern California or the Los Angeles County Economic Development Corporation —who operates the Los Angeles Long Beach World Trade Center—do not loudly advertise the region’s water industry expertise. In fact, on the LACEDC website, one can’t even search for “water” . A notable exception to this general observation is the partnership of California water companies and public agencies who formed the non-profit, CalDesal, to lobby for the passing of the Carlsbad Desalination Plant which would become the nation’s largest desalination plant. The project was stalled in planning for over a decade before being finally approved in 2009 . Construction industry unions, particularly the plumbing union are also very active in promoting local water construction projects. For example, the plumbers union recently helped sponsor the Los Angeles County Economic Round Table’s water industry job analysis and participates in public campaigns on behalf of the water industry . They, along with other construction unions, have been very active in promoting the State’s various water bond measures. Table 9 highlights some of these groups. These organizations produce reports, pass industry information among members and likely hold thousands of events per year. In short, they are at the forefront of knowledge diffusion. These groups do participate in the promotion of the local industry. It is only that the region appears to lack a coordinated regional economic strategy oriented around its water expertise. This differs from the examples profiled in the case studies. These organizations are invaluable in diffusing knowledge. Additionally, California also has a large number of specialized journalist organizations such as the San Diego based, Environmental Business Journal, which is focused on environmental industries. The state is also home to numerous clean technology organizations such as the aforementioned Bay Area Next Ten or the Clean Tech Group, although these organizations tend to be clustered in Norther California. There are also many other active business development nonprofits in California like the aforementioned Imagine H20.

Imagine H20 holds annual technology competitions and teaches inventors how to commercialize. Although, it should be noted that there are relatively few of these organizations, and they are not specifically regional in focus. For example, Imagine H20‘s competitions are open to national and even international entrants .Although this would agree with our observations,rolling benches it would be surprising if it were true, given that others have not noted this function before. Alternatively, glycosylation has been proposed to function in flagellar stabilization and lubrication in P. syringae pv. tabaci, where non-glycosylated flagella formed stiff flagellar bundles. If lack of glycosylation makes the flagella more sticky and prone to breakage, then non-glycosylated mutants might still have functional flagella, but these flagella might break more easily, requiring an enhanced supply of fresh flagellin and/or a lubricating surfactant. Given the co-regulation of BRF with class IV flagellar genes, it was tempting to speculate that FliA, the sigma factor that activates transcription of Class IV genes, might also be directly responsible for regulating brfA expression. However, a disruption of fliA did not abolish surfactant production, and all Class III mutants still produce at least small quantities of the surfactant, indicating that flagellar regulation of BRF production occurs at multiple levels. It remains to be determined exactly how flagella are acting to affect surfactant production. It is also curious that flagella have less of a role in regulating surfactant production in broth conditions, where the surfactant is relatively highly produced. If the function of this surfactant is to lubricate the flagella at surfaces, then why would P. syringae produce such high quantities in broth culture? Although we do not have any evidence of a role for this surfactant in broth cultures, some clues about the surfactant’s properties can lead us to hypothesize possible functions. When large quantities of this surfactant are produced in broth culture by constitutively expressing BrfA we see that this surfactant imparts a milky appearance to the culture supernatants. This is indicative of a surfactant with low water solubility, which most likely associates with surfaces such as the bacterial cell surface, instead of the bulk medium. Therefore, when this surfactant is produced, it likely coats the cells and changes their surface properties. The role of this surfactant in aqueous environments and its effects on cell surfaces and the adhesiveness of cells need to be addressed. As a counter example, syringafactin, a water-soluble surfactant which readily diffuses away from P. syringae, is down-regulated in broth cultures. Thus BRF might best be considered a surface-associating surfactant that modulates the surface properties of either the producing bacterium or the surfaces over which the bacterium must move. Another important clue for the function of BRF was the finding that multiple stress pathways apparently strongly impact its production.

However, where it has been most studied, high osmolarity environments repress motility, and an OmpR knockout is associated with increased flagellar synthesis, increased motility, and also increased production of virulence factors. Such findings are opposite to our observed loss of BRF production in an OmpR mutant of P. syringae. Alternatively, the OmpR homolog in P. aeruginosa, termed AmgR, has been described to function more like the protein conferring membrane stress response, CpxR in E. coli. An examination of the AmgR regulon in P. aeruginosa revealed that it had much less in common with that of E. coli OmpR regulon than that mediated by CpxR, which has been coined a surface sensor. Anecdotally, we have observed that a mutant in the ompR homolog in P. syringae grows well on fresh agar media but exhibits impaired growth on relatively old plates with dried surfaces. In contrast, our mutant screen also revealed the role of two members of the AlgT extracellular stress pathway, both of which when knocked out resulted in an up-regulation of BRF production. The AlgT stress pathway controls the production of alginate in response to membrane stress , and was recently found to similarly influence syringafactin production, with loss of the pathway resulting in up-regulated syringafactin synthesis. It remains unclear why these potentially overlapping stress responses have apparently opposite effects on production of BRF. Further examination of their roles in surfactant production should help elucidate the complex interaction between these two pathways. It might turn out that the combination of these two pathways allows the cell to determine the difference between subtly different stressful situations, only some of which would benefit from surfactant production. It is significant that BRF is produced by an RhlA homolog, which is responsible for the biosynthesis of the rhamnolipid precursor HAA in P. aeruginosa. In P. aeruginosa, HAAs serve to repel neighboring tendrils and maintain an outward motility during swarming. Such a behavior would tend to maximize the ability of a bacterial colony to explore a given habitat by suppressing inward movement, and thus enhancing only outward movement away from colonized areas, and surfactin in B. subtilis has been similarly indicated to have this role. It appears that BRF shares this ability, but it remains to be determined if the swarm repulsion observation has a true physiological function, or is just a laboratory phenomenon that is merely a result of a fundamental physical property of the surfactant. While a syringafactin mutant of P. syringae DC3000 did not apparently make any surfactant and was incapable of swarming motility , we find that such a mutant in strain B728a produces BRF. An examination of the DC3000 genome reveals a close homolog to brfA, but one having a stop codon at the 13th amino acid, apparently accounting for the lack of its production in strain DC3000. P. syringae DC3000 is a poor epiphyte, with low rates of survival on the leaf surface ; it is intriguing to speculate that BRF is not made in DC3000 because it is primarily useful for epiphytic colonization of plants, or alternatively it might be detrimental and/or induce a host response in the apoplast. Restoration of BRF production in P. syringae strain DC3000 should reveal if it can change its virulence or epiphytic fitness. In this study we have utilized an atomized oil assay to identify the biosynthetic and regulatory pathways leading to production of a biosurfactant expressed in a strongly context-dependent way in P. syringae B728a.

The engineers of the Orange County Water District clearly demonstrate this with their willingness to investigate water reuse technologies as a solution to groundwater problems. Hence, the presence of a conservative technocratic civil service of water engineers is potentially a plus for the future adoption of a water reuse infrastructural projects.Institutions are the sets of common habits, routines, practices, rules, or laws that regulate the relations between individuals, networks, and organizations . It is difficult to write comprehensively of institutions as so many of the rules that underlie our conduct are often unwritten or simply established practices or cultural norms that generally go without saying. But the most important institutions are the legal institutions, the laws or ordinances that define the agents of our society and determine the rules of our markets. These laws define the actors—who is a firm, a non-profit organization, a special government agency, an inventor—and identify what rights actors have and how they can legally interact.The Federal and State governments use legal ordinances and tax codes to classify organizations according to legal status. A for-profit corporation has different rights and responsibilities than firms that are organized as partnerships, S-Corporations, sole proprietor ships, or nonprofits. Corporations have limited liability, so employees may lose their jobs and shareholders may lose their investment,nft channel but neither will be liable for the corporation’s debts. Such an organization has long been thought to encourage entrepreneurship and risk-taking . Nonprofits can file under the Federal tax code’s 501 status, granting them tax benefits which can allow these organizations to pursue appropriate goals without the additional burden of potentially onerous taxes. However, these rules also restrict some freedom of action and limit political activity .

Federal and State governments also arbitrate important legal instruments such as patents or financial tools like stocks and bonds. Our system of patent protection grants inventors a right to exclude others from making, using, selling, offering for sale, or a whole manner of other activities of their patented product or process for twenty years . This gives the patent holder a monopoly ensuring they have ample opportunity to profit from their invention. Financial instruments, such as the tax exempt municipal bonds discussed above, are another legal instrument that have a profound impact on the working of our economy. Generations of legal philosophers have composed libraries debating the theories of our various legal tools, and I have no interest in attempting to wade into such ground here. Here I will turn briefly to water rights—and particularly ground water rights. These legal instruments have a direct bearing on our study of Southern California’s burgeoning water reuse industry. In fact, they were central to Orange County’s groundwater reuse project, and will be critical for the potential growth of additional projects. Since the adoption of the 1928 reasonable use use doctrine, California water is protected for the use and benefit of all Californians . Water cannot be outright owned by individuals, groups, businesses, or governmental agencies. The state issues permits, licenses, and registrations to give individuals or organizations the right to use “reasonable amounts of water” . Like our collective legal system, water rights in the United States largely evolved from the English Common Law system. However, California has a long tradition of water litigation which has led to a “California Doctrine” that differs significantly from prevailing US norms . The California doctrine recognizes rights as valid if they are based on one of three factors: riparian rights—ownership of land near watercourse; appropriative rights—prior use of water, and groundwater rights—title of water rights underneath land. English common law traditionally valued riparian rights and granted land holders near absolute groundwater rights.

Appropriative rights privilege early water users over later users and became a common practice as settlers moved into arid American west to maintain peace. They are without basis in traditional English Common Law . California further broke with the English Common Law tradition by finding that groundwater was not solely the property of a land owner. Instead, California has a complex system based on both the rights of the landowner and a correlative rights tradition. Correlative rights are similar to riparian rights in that they are based on proximity to water, or in the case of groundwater, physical contiguity.Although Statewide there are only 22 adjudicated water basins, meaning that the rights have been settled and every individual or organization with a claim can use water but only in a sustainable manner, most of these are in urban areas . Adjudication can limit the freedom that a managing entity has over groundwater basins, often requiring additional negotiations. Sometimes these negotiations turn into difficult court cases . This is even further complicated if the groundwater basin is polluted, such as Los Angeles’s heavily industrialized San Fernando Valley where legal mandates have been handed down requiring that the various water rights holders must clean up the basin . Adjudicated basin agreements were primarily designed to control the allocation of water supply, not replenishment or the removal of contaminants, so this is still relatively unchartered legal territory . Overall, Southern California is rich in groundwater potential, with a total estimated available capacity in MWD’s service area of 3.2 million acre-feet. , however these reserves have been regularly over drafted . California law allows the creation of special districts to manage or replenish water sources. Today several districts, most notably the Water Replenishment District of Southern California , have plans to purchase excess MWD water and inject it into groundwater basins . However, there are complex legal issues involved in groundwater replenishment, particularly in adjudicated basins. WRD’s plan to inject 450,000 AF over two wet years when MWD water was plentiful was blocked in 2009 by a lawsuit from Central Basin Municipal Water District and the cities of Downey, Signal Hill, Cerritos, and the Tesoro Oil Company who protested the plan . In May 2012, the State Supreme court voted in favor of WRD. In 2012 water prices have risen, reflecting the drier weather of 2011,hydroponic nft which will make the groundwater injection plan much more costly. Additionally, untold millions in legal fees have been squandered on such inter agency lawsuits over groundwater.

Furthermore, attempts by the State to adopt new groundwater regulations have been strongly opposed by land owners, particularly agricultural interests and local water districts who are fearful that new rules will limit freedom of water use . In short, regional groundwater management is at best, inefficient, and at worst dysfunctional. Efforts to introduce truly comprehensive water management solutions, such as low impact development ordinances that mandate onsite storm water management that promote groundwater replenishment through natural processes of soil percolation are further hindered by additional institutional complexity. Cities control planning and land use, yet the state transportation department oversees the roads, while various public and private entities control land. It is very unlikely that California will ever see anything as far reaching as Netherland’s or Singapore’s recent reforms that created single ministries responsible for comprehensive water management. The complex legal structure that underlies groundwater rights in California has already had a major impact on the water reuse industry, and continues to in three primary ways. First, the Orange County Water District would not exist without being set up to protect the groundwater basin, and therefore never would have built Factory 21. Water districts with groundwater basins that are over-drafted, under threat of seawater, or are contaminated have an incentive to use the cheapest water that they can to replenish their supplies, therefore they may turn to water reuse as a source. Secondly water rights are one of the largest determinants of water price, which is the largest determent of private investment in innovative technologies . How an individual or a utility obtains its water supply is a huge factor in the price it pays for that water. For example, if a utility has ample high-quality groundwater sources available, its rates will be lower than if the utility needed to purchase or import its water supply . Conversely, if a utility does not have groundwater and needs to import its water supply, the cost of that water will almost always be higher. In Southern California, a water district or company with easily accessible groundwater has the freedom to choose its sources; it can purchase imported water from MWD when prices are low and pump when prices are high; these districts are unlikely to give up this low cost advantage. The legal complexity over adjudicated ground basin might persuade some districts to turn to water reuse. It is fairly clear that OCWD’s groundbreaking GWRS project would not have been undertaken without the alignment of groundwater water rights, storage capabilities, and clear compelling need. In my investigation I found that GRWS managers were certain that their complete control of the aquifer was critical to moving forward with the project .

Additional lawyers of complexity would have added costs and risks which might have imperiled the project . Market demand is the primary motivation behind new products or technologies, and the water industry is no different. If sufficient demand exists to justify investment, investment will often be made. In a market economy, if the cost is high then firms will seek out innovations—and it is hoped—be rewarded with market share. Specialized demand conditions often distinguish a regional industry and meeting that demand will often impart an advantage to the region. Water is not a product that is manufactured, nor is it strictly speaking, a commodity that is dug from the ground, but rather it is more a hybrid product that is both a renewable resource in the manner of agriculture that needs to be collected and transported, but also a product that can be derived from a recycling process. Furthermore, the water economy is not truly a market economy, for water is a public good that is critical to the functioning of our region. Water will often be delivered regardless of costs, and benefits greatly from implicit public subsidies. Water delivery is also a natural monopoly as the majority of its costs are infrastructural, the cost of physically placing pipe to carry water is very high and thought to account for up to 80% of the price of water , which is a significant barrier for potential competition. But like other markets, the primary driver behind innovation in the water technology industry is the cost and/or availability of water. If supply is limited and price is high, then investments will be made in technologies and/or process innovations. The four principle factors in the Southern California region are the availability of groundwater, weather , infrastructural capabilities, and legal constraints . The first three are fairly straightforward; rain needs to fall, the water needs to be accessible and the infrastructure must exist to collect it, clean, and deliver it. Legal constraints include considerations of legal water rights—who has claim to the water—as well as government mandates such as the Owen’s Valley court decision that limited water withdrawals for environmental causes, or the conservation mandates imposed during droughts. In practice, the diverse circumstances faced by the myriad of Southern Californian water agencies—regional wholesalers, distributors, local retailers, reclamation districts, replenishment districts, and private water companies—results in equally diverse pricing schemes making it difficult to identify the true cost of water in Southern California, and hence potential savings from investment in efficiency or technology improvements. Industry analysts have repeatedly cited the lack of transparency in water pricing, and particularly, the hidden subsidies, as impairing potential investment in water technologies . In my case studies, both Singapore and Australia made identifying the true cost of water a central platform in their respective water reforms to both encourage conservation and efficient allocation . Few Californians know how much it really costs to deliver water. All Interviewees working in the water industry agreed that California pricing schemes were confusing, and nearly all expressed a desire for prices to rise in order to increase investment . One notable exception worked for a public agency that delivered water. They agreed that truer pricing regimes would increase investment but also pointed out that cheap water was in keeping with their agencies public mission .

Japanese technology conglomerates such as Mitsubushi, Toray, Kutuba, and Asahsi dominate many of the most advanced water treatment processes and therefore would merit further study. Among wastewater treatment suppliers, Madrid, Spain, also has a striking concentration of firms , and like Israel, Singapore, and Australia, Spain also recently embarked on major water market reforms . French and British Multinationals such as Veolia and United Water dominate the global privatized municipal urban water delivery services market , a curiosity that would also invite further inquiry.Two locations, Israel and Singapore, consistently top the water industry literature as having the most technologically developed industries, a fact which was further verified through several of my industry interviews. The Netherlands is home to the world’s largest and most important water services engineering firms, as well as hundreds of technology companies and several globally prominent research centers . In comparison, Australia has a much smaller impact on the water technology industry. It is also more than a region being a large country, the only one to encompass an entire continent, although 85% of the population lives in the temperate south eastern coastal region. I chose to include it for three principle reasons. First, Australia shares many similarities with Southern California. Both are largely arid climates. Both share Anglo Saxon legal and business traditions, as well as strong industrial histories based on natural resource extraction, and both are now heavily urbanized. Like southern California, Australia has recently witnessed major growth in water technological innovation—through industrial investment in water reuse technologies ,ebb flow table infrastructural investment in desalination and reuse plants and huge growth in domestic water technology patent production . In 1994, Australia began a series of major reforms to its water industry, removing water subsidies and separating regulating utilities from service delivery firms.

Since that time, the country has witnessed an increase in water productivity of more than 50 percent. In contrast to southern California, however, Australia has also embraced an economic growth strategy centered on the exportation of goods and services. Finally, I also felt it important to explore domestic centers of water technology. Milwaukee, Wisconsin has embarked on a strategy to become a global center of water technologies led primarily by the private sector. In 2008, the US Federal government targeted the Tri-State region around Cincinnati for the development of a water innovation system focused on water cleanliness. During the course of my research, I discovered that California’s own San Joaquin Valley has actively pursued a water technology investment cluster strategy targeting water flow technologies and I would be remiss if I did not include a discussion of the efforts to build this water technology innovation system into an economic growth engine. I found that many of the irrigation firms active in San Joaquin Valley are also active in Southern California. It is important to point out that the following summaries are only a cursory exploration of the water technology innovation systems active in each of the case studies. They are not meant to be comprehensive, but simple summaries of the key components and economic strategies of the respective water innovation systems. renowned in irrigation, water treatment, and flow control technologies. The country currently boasts over 70 emerging water technology start up firms . The water sector generates over $1.1B in xports, but is targeted to generate more growth in the future . The Israeli government also has a strong history of strategic economic development, targeting research and development and setting out business incubation. Since 1994, Israel also has had an active economic clustering program known as MAGNET—the Hebrew acronym for Generic Pre-Competitive Technologies and R&D . Today the country has 41 active economic clusters, including a water technology cluster centered in Ashekelon . The occasion of Minister Ben Eliezer’s speech was the unveiling of a new national government initiative, Novel Efficient Water Technologies program, or simply “NEWTech” . NEWtech is designed to increase coordination between government agencies, academic institutions and private firms in order to increase water technology innovation and exportation.

The program calls for the water technology industry to become a main growth engine of the Israeli economy . This is laid out explicitly in the government mandate “New Governmental Decision Number 157: Development of Water Technology in Israel” which calls on the country to recognize “the latent potential that water technology could have on the Israeli economy; and on the importance and centrality that government and private companies have in this market, in Israel and in the exporting industry.” The declaration continues by calling for the government to “examine the methods and the means that different governmental offices can use to support the development of water technology, from the R&D stage to the manufacturing and exporting stages impacting irrigation practices around the world” . Israeli water economy boosters like to point to the biblical story of Moses drawing water from the rock to show the historical importance of water to Israel , and it certainly has been important to the modern state. The early Zionists that left central Europe for the arid British protectorate came to build a community of Jewish agriculture communes, Kibbutzim . In Palestine, traditionally water was considered a right for all residents ; however, in contrast to central Europe, the region did not have abundant water supplies. Furthermore, native residents were often fearful of the new Zionists and hostilities occasionally broke out. During the post World War II British decolonization period, this enmity escalated into a full-scale regional war when the State of Israel was declared in 1948. The young state prevailed and then expanded again after another regional war in 1967. Today, the ongoing Israeli/Palestinian dispute continues to define the Middle East, leaving Jewish Israel largely isolated among its Muslim neighbors. Unable to cooperate with neighbors to secure additional water supplies, Israel has had to rely entirely on its own territory for sufficient water for agriculture, a fact that likely contributes to Israel’s ongoing military occupation of the internationally recognized Syrian territory of the Golan Heights—the source of the country’s largest river, the Jordan—and continuing occupation of the Palestinian territories,hydroponic grow table where large groundwater aquifers exist . Additionally, Israel is blockaded from importing oil from Muslim producers, which has put a significant damper on the country’s energy capabilities and likely unleashed a frantic search for alternatives.

In 1937, over a decade before the country itself was formed, the settlers formed the predecessor to today’s state water company, Mekorot Water Company, in order to manage water supplies. Today Mekorot provides Israel with 90% of its drinking water and 80% of total water . In the 1950’s the country passed a series of water management laws requiring: metering , drainage and flood control , permits for it’s use —all of which consolidated the public’s ownership of water and the government’s role in management . In the 1970’s, Israel embraced water demand management as a technique to further promote efficient use of water, and to promote the use of water and energy saving technologies. Appropriate pricing regimes were implemented to discourage waste. Having central government control over water and water infrastructure made this an easy policy to implement. At the same time, the country’s water research institutions continued technological invention, improving drip irrigation, advancing techniques such as reverse osmosis, and improving filtration methods critical to desalination and water reuse . In 1997 Israel built the world’s first Reverse Osmosis plant that was designed to treat both seawater and discharged brine, which it received from an adjacent desalination facility at Elilat . In 2001 Israel sought international help in order to scale up and build the world’s largest RO desalination plant. The country contracted with VID, a special purpose joint-venture company made up of two Israeli firms, IDE Technologies and DanknerEllern Infrastructure, and French water services multinational Veolia , previously Vivendi, to design, build, and operate the Ashkelon desalination plant . IDE Technologies is itself a partnership of Israel Chemicals and the Delek Group. After 25 years the plant will be transferred to Israel. In addition to the required facilities for seawater pumping, brine removal, water treatment, and membrane desalination units, the complex project required laboratory buildings for ongoing testing purposes. Today, Ashkelon generates nearly 6% of Israel’s water supply, most importantly its utilization of advanced RO technologies and economies of scale have given it the cheapest water in the world. It is one of several plants that have been planned for the coast . The international partnership with Veolia further embeds Israeli firms into the advanced water technology scientific and business networks, enhancing knowledge creation and diffusion and increasing market opportunities. In addition to Veolia, Israel has business relationships with global water technology firms Siemens, GE, ABB, Dow Chemicals, and Jain Irrigation Systems. Israel also has formed strategic partnerships with public water entities throughout the world with governments and municipalities in China, Singapore, Beijing, Madrid, Melbourne, Sao Paulo, Buenos Aires, and several others . They are also in close contact with California entities such as the LADWP and the OCWD . Outside of exceptional infrastructural projects like the Ashkelon plant, the state water firm Mekorot owns the majority of the water infrastructure, over 3,000 water works that encompass all phases of the water process, most notably wastewater management . Throughout much of its history, Mekorot partnered with The Tahal Group, an engineering services firm, to build the water infrastructure. Today The Tahal Group is an international firm headquartered in the Netherlands. Prior to the mid 1990‘s when it was privatized, Tahal was an Israeli military contracting and engineering firm specializing in infrastructure . This type of partnership between the state, military, and private firms is common in Israel . It continues today with Mekorot often partnering with local firms to build infrastructure and test technologies. Many of these firms have either been spun off from the military or are closely involved with military projects. The close collaboration between the state, the military, and technology firms, has long been a central feature of the Israeli technology economy. Dan Senor and Saul Singer recently wrote the best seller book Start-up Nation that attempts to explain how Israel has thrived in the high technology economy . They argue that the entrepreneurial culture of market savvy independent thinkers bound by close connections wrought through shared military service, and honed by the military’s appetite for advanced research technology, has created the conditions for the explosion in high technology companies. Israel has over 70 companies listed on the US NASDEQ market—the most of any non US country . Additionally Israeli scientists have been at the forefront of a long list of technological innovations, such as CT scanners, advanced Intel microprocessors, AOL’s instant messenger, zip compression technology, the aforementioned drip irrigation, and many more . Israel also greatly benefits from the vast knowledge and international connections of the global Jewish network, most notably in the United States where Jews are well represented in science, business, academics, law, media, technology, and professional fields. Israel is central to Jewish identity and many American Jews make great efforts to ensure its safety and economic vitality through tying the country tightly into our global economic system. The close connection between the military and entrepreneurs has also been deliberately fostered through an economic development strategy of national technical business incubators as well as the creation of a venture capital industry. The government effectively jump started the venture capital industry in the early 1990’s with the creation of Yozma program to invest in high tech ventures . The country also targeted “clean technologies”, such as water technologies and the renewable energy industry. This is partially due to its limited resources, but also due to the oil embargo implemented by oil rich Muslim nations.For example, Kinrot Ventures was founded in 1993 as part of the Israeli Incubator Program as the world’s first clean tech water technology incubator . Today Kinrot Ventures is one of the most important water venture capital firms in the world. Kinrot targets emerging companies with potentially disruptive water technologies, with a specific focus on advances in purifying, filtering, desalination, transporting, and storing water.

A common pathway in most organisms for detoxifying xenobiotics is through glutathione conjugation catalyzed by glutathione Stransferases . It has long been recognized that GSTs play an important role in normal cellular metabolism in plants . In addition, GST mRNA responds quickly to exposure of xenobiotics , protecting the cell against oxidative stress or chemical toxicity . Previous research on xenobiotics such as herbicides shows that differences in GSH availability and in the portfolio of GST isoenzymes are associated with xenobiotic resistance . Conjugation with various biomolecules was observed in plant metabolism of different PPCPs, including diclofenac , ibuprofen , triclosan , benzotriazole and acetaminophen . However, GST-mediated conjugation may play a predominant role, but has been relatively understudied so far . In particular, the entire process of GST mediated detoxification, from GSH conjugation in the cytoplasm to vacuolar accumulation and processing of conjugates has yet to be elucidated in vivo. Acetaminophen and structural analogs are phenolic compounds that are among ubiquitous environmental contaminants . Acetaminophen is one of the most used pain and fever relief medicines, and many billions of doses of acetaminophen are consumed each year . Acetaminophen was detected in the aquatic environment at 0.01–0.3 mg L−1 in the South Wales region of the UK .Cucumber is a crop plant, widely consumed, with high economic and ecological relevance,hydroponic grow system and recommended for use in phytotoxicity studies by U.S. Environmental Protection Agency . In this study, we used acetaminophen to elucidate the mechanisms of GST-mediated detoxification in cucumber plants.

Findings of this study may provide evidence for PPCP detoxification via GSH conjugation, and will likely prompt further exploratory investigation on the role and value of this pathway for the numerous emerging contaminants.Cucumber seeds were obtained from Fisher and transferred to a 72-hole plate filled with a mixture of vermiculite and perlite . Plants were cultivated under controlled conditions for 1 week and irrigated with half strength modified Hoagland nutrient solution, which is adequate for the seedlings’ energy demands for cucumber growth and the low ionic strength nutrient solution permits a more precise computation of acetaminophen speciation than do more complete nutrient medium. Details on the solution composition are given in Table S2. Seedlings in the third-leaf stage were removed from the pots, rinsed with tap water, and placed in 500 mL glass jars containing aerated, half strength modified Hoagland nutrient solution. Each treatment contained three replicates, and each replicate was prepared from a single plant by separating into roots and shoots.After 7 days of adaption, plants were exposed to acetaminophen by spiking 25 μL stock solution to yield an initial concentration of 5.0 mg L−1 .Simultaneously, treatment blanks and plant blanks were included in duplicate to determine abiotic losses of acetaminophen under the experimental conditions. All experimental materials were auto-claved, 121 °C for 30 min, before use. A parallel group trial enrolled with acetaminophen at 60 μg L−1 was included to simulate more realistic levels and to validate the high level treatment. The cultivation lasted for 20 days, with the nutrient solution renewed every other day . Additionally, in order to determine if plants can detoxify acetaminophen via GSH conjugation in realistic field environment, cucumber seedlings were cultivated for 20 days in soil amended with 5% bio-solids containing acetaminophen at an initial concentration of 10 mg kg−1 .

A root exudate control was included to evaluate the effect of plant exudates on microbial degradation and GSH conjugation of acetaminophen in the hydroponic solution. Cucumber seedlings were cultivated in 500 mL glass jars containing aerated, half strength modified Hoagland nutrient solution, and the plants were removed after 7 days. The solution was brought back to 500 mL with half strength modified Hoagland nutrient solution, and then 25 μL of acetaminophen stock solution was added to yield an initial concentration of 5.0 mg L−1 . The nutrient solution samples were exposed to the same conditions, and were analyzed for acetaminophen and its conjugates. To investigate whether GSH-acetaminophen can be transported from the root to the shoot, two-week-old cucumber plants were exposed to 1 mg L−1 GSH-acetaminophen for 2 days. Leaves were collected and extracts from the aerial parts were analyzed as described below. To test whether cytochrome P450 was involved in GSH-conjugates formation, two P450 inhibitors, 1-aminobenzotriazole and piperonyl butoxide, were used to pretreat the plant on the basis of previous studies demonstrated specific inhibition effects . Cucumber seedlings were pretreated with 1- aminobenzotriazole or piperonyl butoxide for 12 h in 500 mL glass jars with aerated, half strength modified Hoagland nutrient solution, followed by spiking 25 μL of acetaminophen stock solution to yield an initial concentration of 5.0 mg L−1 . After 96 h incubation, tissue samples were collected from both the treated and untreated plants.The specificity of these P450 inhibitors was evaluated by monitoring cytochrome P450 activity, GSH content and GST activity in cucumber tissues after the treatment. For better clarity, all the experiments performed was schematically represented Table S3. Simultaneously, commercially available common bean , tomato , alfalfa and wheat seeds were germinated and transplanted under the same conditions as above. After 7 days of adaption, plants were exposed to acetaminophen at 5.0 mg L−1 . After 96 h, plant roots were collected and analyzed for acetaminophen and its glutathione, cysteine and N-acetylcysteine conjugates.

Sampling, sample preparation and analysis Cucumber seedlings treated with or without 5 mg L−1 acetaminophen were sacrificed at 0, 12, 24, 48, 72, 96, 120 and 144 h. Before sample preparation, roots were rinsed thoroughly with tap water. Harvested tissues were separated into roots and shoots and then frozen in liquid nitrogen. Enzyme activities of GST, glutathione reductase , γ-glutamylcysteine synthetase , and cytochrome P450, as well as contents of reduced glutathione in both roots and shoots, and lipid peroxidation were immediately analyzed after sampling, as described below. The remaining plant samples were freeze-dried and stored at −80 °C until chemical analysis. At each sampling time, nutrient solution samples and the aqueous root exudate samples were collected and mixed with equal volumes of methanol. The mixture was added with d4-acetaminophen as a surrogate, filtered through a PTFE syringe filter and stored at −20 °C before analysis. To quantify acetaminophen and its glutathione,indoor garden cysteine and Nacetylcysteine conjugates, the freeze-dried plant tissue samples were ground to a fine powder with a mortar and pestle, and a 0.5-g aliquot was used for solvent extraction. Each sample was spiked with d4- acetaminophen as the recovery surrogate, and extracted, sequentially, with 20 mL methyl tert-butyl ether , acetonitrile, and 0.5 mM HCl solution in an ultrasonic water bath for 20 min for each extraction. The supernatant from MTBE and acetonitrile extraction was combined after centrifugation and reconstituted in 1.0 mL methanol after drying under nitrogen . The extract was pooled with the supernatant from the HCl extraction. The pooled extract was loaded onto an Oasis™ HLB cartridge that was preconditioned with 6 mL methanol and 12 mL deionized water, and eluted with 15 mL methanol under gravity. The eluate was evaporated to dryness under N2, and the residue was recovered in 1.5 mL methanol:water mixture and filtered before analysis. The instrumental analysis was performed on a Waters ACQUITY ultra-performance liquid chromatography coupled to a Waters Micromass Triple Quadrupole mass spectrometer equipped with an electrospray ionization interface . Acetaminophen, and its glutathione, cysteine and N-acetylcysteine conjugates were separated using ACQUITY UPLC BEH C18 column with water and methanol as mobile phases. Electrospray ionization was operated in the positive mode. Detailed information on the instrumental analysis is given in Table S4.Fresh cucumber roots were frozen in liquid nitrogen, and homogenized on ice with 5 mL of 50 mM potassium phosphate buffer containing 1 mM EDTA and 1% polyvinylpyrrolidone. After centrifugation at 15,000 g at 4 °C for 20 min, the supernatant was used for the assay of activities of glutathione S-transferase, glutathione reductase, and cytochrome P450 . Measurement of GST activity was carried out spectrophotometrically after the glutathione and 1-chloro-2,4-dinitrobenzene adduct synthesis reaction . Briefly, GST activity was measured in 2 mL of a reaction mixture containing 50 mM PBS , 1 mM CDNB, 5 mM GSH and 100 μL enzyme extract. The increase in absorbance as a result of GSH-CDNB synthesis was determined at 340 nm for 5 min on a Cary 50 UV– Visible spectrophotometer . The GST activity was calculated using the extinction coefficient of GSH-CDNB .

To determine the activity of GR , a 200 μL aliquot of enzyme extract was added to the reaction mixture of 0.15 mM NADPH and 0.5 mM oxidized glutathione in 50 mM PBS . The absorbance decrease was monitored at 340 nm for 3 min after GSSG-dependent consumption of NADPH . For the assay of γ-ECS , plant tissues were homogenized and suspended in 5 mL of 0.1 M HCl. After centrifugation at 20,000 g for10 min at 4 °C, the supernatant was collected. The γ-ECS activity was measured according to Shan and Liang . An incubation solution was prepared with 800 μL 50 mM TrisHCl containing 0.25 mM glutamate, 10 mM ATP, 1 mM dithioerythritol, 2 mM cysteine, and 400 μL of the γ-ECS sample. The mixed solution was incubated for 1 h at 25 °C, and then 800 μL phosphorus agent was added and mixed. After incubation at 45 °C for 25 min, the absorbance at 660 nm was measured on the UV–Visible spectrophotometer. One unit of γ-ECS activity was defined as 1 mmol cysteine-dependently generated PO4 3− per minute. The levels of proteins in the enzyme extracts were determined using Coomassie Brilliant Blue G-250 . Brieflfly, 100 μL of enzyme extract was added to 5 mL of 0.01% Coomassie Brilliant Blue G- 250. After 5 min, the absorbance at 595 nm was measured on the UV– Visible spectrophotometer. The protein content of enzyme extracts was calculated by comparison with a standard curve using bovine serum albumin as the standard. The protein concentrations in the extracts were estimated using the BSA standard curve. The content of GSH was determined spectrophotometrically according to Jiang et al. . Plant tissues were homogenized in 5 mL of cold 5% meta-phosphoric acid on ice and centrifuged at 12,000 g at 4 °C for 15 min, and the supernatant was analyzed for GSH. To 0.5 mL of supernatant, 0.5 mL PBS and 0.5 mL of 5′5′-dithiobis-2- nitrobenzonic acid were added. After thorough mixing and incubation for 5 min, the absorbance at 412 nm was measured . Membrane lipid peroxidation, a typical indicator of stress phytotoxicity , was estimated by measuring the concentration of malondialdehyde, according to the reaction with thiobarbituric acid as described in Sun et al. .All treatments were performed in triplicates. A procedural blank and a sample duplicate were included in every batch of 10 samples to monitor background contamination and reproducibility, and the calculated relative standard deviations were b10%. The d4-Acetaminophen was used to account for any loss during sample preparation, matrixinduced ionization effects, and variations in instrumental response. Authentic standards were used to confirm the target analytes. A six-point calibration line was used for quantification with the r 2 values of at least 0.99 for all analytes . No acetaminophen or any of the conjugates was detected in the solvent or treatment blanks. Limits of detection and quantification for individual acetaminophen and the conjugates were calculated as 3 and 10 times the signal-to noise level from the low-level spiked samples . The recoveries in all samples were within acceptable limits ranging from 75 to 110%, demonstrating good method accuracy and precision. Extraction efficiency was N91% for acetaminophen and its conjugates. The plant position was regularly rearranged every 2 days to avoid side-effects.The level of acetaminophen in the nutrient solution without plant, after the removal of plant , or with cucumber plant, all decreased over time . Significant losses occurred in the unplanted control or the root exudate control . Considering that the cultivation system was not a sterile environment, both microbial and abiotic degradation may have contributed to the apparent acetaminophen dissipation in the solutions. This observation was consistent with Bartha et al. , who also reported the occurrence of plant-independent, biotic processes that decreased the available acetaminophen in plant solution.

Plant health and development are influenced by a broad range of microorganisms inhabiting the root rhizosphere, including beneficial associative bacteria. These bacteria are usually minor components of the rhizosphere microbial community but have been shown to significantly enhance plant growth and yield . This ability to enhance plant growth has been attributed to diverse mechanisms, including biological nitrogen fixation, production of phytohormones, enhancement of nutrient uptake , and bio-control of pathogens and pests . Plant growth-promoting bacteria can colonize roots either on the root surface or as endophytes without eliciting a noticeable plant defense response. Unlike some other bacterium-plant interactions that show strict host specificity, many PGPB can colonize a wide variety of plant species, including agriculturally important members of the Poaceae family, such as rice, maize, wheat, and a variety of bio-energy grasses . PGPB strains have been described for several host plants, including Setaria viridis, a model C4 plant, which is a close relative to a variety of bio-energy grasses. In a previous study, we demonstrated that S. viridis under lab conditions can obtain up to 100% of its nitrogen needs through biological nitrogen fixation mediated by diazotrophic PGPB . Among the strains used were the betaproteobacteria Azoarcus olearius and Herbaspirillum seropedicae, which exhibit strong growth-promoting ability . Azoarcus olearius DQS4T was originally isolated from oil-contaminated soil and, based on its genome sequence, this strain shows high similarity with the well-studied A. olearius strain BH72 . Strain DQS4T can colonize the roots of rice and Setaria to high levels and increase below- and above-ground biomass . H. seropedicae SmR1 is a well-studied endophytic bacterium that colonizes several plants, including maize, wheat, and Setaria. Recently,container size for strawberries in situ metabolomic profiling of S. viridis roots colonized by SmR1 demonstrated that inoculation induced a wide variety of plant metabolic changes, including those affecting nitrogen and phytohormone levels .

Thus, similar to many other, better-studied plant-microbe associations, PGPB inoculation appears to profoundly affect the metabolism of its host. To identify specific PGPB genes that contribute to plant root colonization, we applied transposon mutagenesis sequencing coupled with random barcoding. This technique assesses gene functionality in mutant strains through the generation of reusable libraries of unique and mapped mutant insertions.TnSeq is a powerful and sensitive approach to identify bacterial gene functions that play roles in bacterial fitness under researcher-defined growth conditions . Starting with information on the location and frequency of each mutation in the population, the change in mutational frequency after passage of the population through an environmental challenge leads to the identification of genes that are either essential, important, or detrimental to growth under that condition. For example, TnSeq of Streptococcus pneumoniae identified genes essential for bacterial basal growth, as well as genes involved in transcriptional regulation and carbohydrate transport . In the PGPB Pseudomonas simiae, TnSeq revealed genes involved in carbon metabolism and motility that could enhance or suppress colonization of Arabidopsis roots . In the present work, we applied standard TnSeq and a variant of TnSeq that uses random DNA barcodes to measure strain abundance to construct mutant libraries of strains DQS4T and SmR1, respectively, and to then evaluate genetic contributions to fitness on the host plant Setaria viridis.Gene essentiality is defined as its importance in maintaining competitive fitness under a condition of interest . For this study, two PGPB bacterial species were used, Azoarcus olearius DQS4T and Herbaspirillum seropedicae SmR1, both diazotrophic and capable of promoting plant growth . The mutagenized pool of each strain was inoculated onto Setaria viridis roots or a carbon augmented soil control with no plants.

Root-associated bacterial cells were recovered, transposon DNA was sequenced, and resulting reads were mapped to each bacterial genome. The relative incidence of a specific mutation was then determined and used to calculate fitness values. By high throughput sequence analysis of insertion mutants, we covered about 3,692 genes of DQS4T and 3,878 genes of SmR1 distributed throughout either strain’s genome. Thus, regardless of method, very good coverage of each genome was achieved. In the case of DQS4T transposon mutagenesis, 89.2% of 4,135 total genes were mapped to a gene harboring at least 1 insertion event. For the SmR1 library, 81.1% of the 4781 genes had identified mutations. We assume that genes without an insertion in the library likely identify those essential for bacterial growth in culture. Our screening identified 89 and 130 gene mutations that significantly affected the ability of strains DQS4T and SmR1 to colonize S. viridis roots, respectively. Given that our interest was to identify genes that exclusively affected root colonization, we excluded from further consideration any genes that also affected fitness under soil conditions . The genes affecting root colonization were categorized based on the phenotypes as either enhanced fitness value, mutations that increased root association ; or decreased fitness value, mutations that impaired root association . For the complete list of gene mutations affecting fitness under each condition, see Table S2. Unsurprisingly, many of the genes identified lacked a clear functional annotation, especially for A. olearius DQS4T . Even though each strain showed a distinct pattern of mutations that affected fitness, a few common gene functions were identified impairing root colonization in both strains. The most common COG categories important for SmR1 root colonization were those involved in amino acid transport and metabolism, followed by energy production and conversion and coenzyme transport and metabolism. In the case of DQS4Tthe most common COGs were cell wall/membrane/envelope bio-genesis and signal transduction, followed by translation, ribosomal structure and bio-genesis, and inorganic ion transport and metabolism .

Although we cannot rule out that the different mutagenesis methods could contribute to the different fitness profiles, the overall mutational coverage of the genomes of both strains suggest that such effects are likely minor. Hence, the results seem to suggest that any given PGPB strain will have different major requirements for root colonization reflecting the specific metabolic needs of the bacterium.Gene mutations that positively impacted the ability of bacterial strains to colonize roots were defined as those with a fitness score $ 1. We identified 8 and 14 genes in this category in A. olearius and H. seropedicae, respectively . This list included the Azoarcus gene predicted to encode a pyrroloquinoline quinone -dependent alcohol dehydrogenase , which is involved in the oxidoreductase process of ADH. Based on sequence alignment with Azoarcus olearius BH72,container size for blueberries the DQS_RS19730 gene encodes an ExaA5 protein that was previously reported to be induced upon exposure to ethanol as a carbon source . In our study, we found that exaA5 plays an important role in root colonization. Disruption of this gene enhanced root colonization of S. viridis roots . However, the mutant was less competitive in root colonization than the wild type at 1 and 3 days after inoculation but seemed to recover to wild-type levels by 5 days after inoculation . An insertion mutation in the gene encoding a diguanylate cyclase significantly increased bacterial root colonization 3 and 5 days postinoculation and showed the same trend in competition with the wild type . Diguanylate cyclases with a GGDEF activesite motif produce cyclic di-GMP and play a major role in the transition between motile and sessile bacterial lifestyles . We also identified an iron regulator outer membrane protein, TonB , presumably required for Fe31uptake . This protein was reported to interact with ExbA and ExbB, forming a complex that regulates iron acquisition . In SmR1, 6 of the 14 gene mutations that increased root colonization are predicted to play a role in flagellar biosynthesis. FliF, FliG, FlhB, and FliQ are structural components of the flagellar basal body . MotA is complexed with MotB and functions as a proton channel for torque generation . Our testing showed that the absence of flagellar genes in the SmR1 strain conveyed an advantage for root colonization in S. viridis 10 days after inoculation. We also identified a poly-3-hydroxybutyrate -related gene, a poly-3-hydroxyalkanoate depolymerase PhaZ1 , that enhanced colonization ability when mutated . PhaZ1 is a PHB depolymerization enzyme required for the granule mobilization . Furthermore, mutations in the genes encoding transcriptional regulators and ABC transporters also resulted in increased root colonization by strain SmR1 .Mutant strains corresponding to 81 DQS4T and 114 SmR1 genes were identified as significantly reducing root colonization . Therefore, these gene functions are normally required for efficient colonization by wild-type bacteria. Within this group of mutations, we identified two genes present in both DQS4T and SmR1: cheY , which is related to chemotaxis, and ampD , which is involved in peptidogly can degradation. Chemotaxis is directly involved in modulating the movement of the flagellum in response to attractants, helping bacterial orientation and active motion for survival toward favorable conditions .

In addition, four other genes encoding transmembrane chemoreceptors, also known as methyl-accepting chemotaxis proteins , were identified in H. seropedicae. The protein CheA undergoes autophosphorylation induced by MCPs, and CheR and CheW acts to modulate the phosphorylation state of CheY . Mutations in these genes impaired the capacity of H. seropedicae to colonize roots, consistent with a previous report .Analysis of the DQS4T TnSeq data identified a gene predicted to encode a two-component sensor histidine kinase containing a HAMP domain involved in signal conversion between the transmembrane-sensing and kinase activity control . One assumes that this histidine kinase is reacting to an unknown factor in the rhizosphere that normally enhances root association in wild-type cells. We also observed genes involved in cell wall formation, such as murI , a glutamate racemase responsible for the conversion of L-glutamate in D-glutamate, and murA , a UDP-N-acetylglucosamine 1-carboxyvinyltransferase responsible for converting UDP-N-acetylglucosamine to UDP-N-acetylglucosamine enolpyruvate. A previous study of H. seropedicae reported the importance of the mur genes for maize root association and also showed that their expression was repressed in the presence of naringenin. In addition, a N-acetyl-anhydromuranmyl-L-alanine amidase AmpD, likely involved in the degradation of peptidoglycan by hydrolysis of muropeptides that can serve as signals for induction of b-lactamase , was identified as important for root colonization in both strains. We also identified a putative transcriptional regulator of catechol 2,3-dioxygenase, a flavonoidrelated compound that might be involved in the degradation of aromatic compounds important for plant-bacterial interactions . Among such compounds are flavonoids that can serve as chemoattractants for rhizobia in legumes . Flavonoids can also mediate PGPB colonization, as reported for H. seropedicae colonization of Arabidopsis and the colonization of rice by Serratia spp. . Interestingly, mutations in genes involved in PHB metabolism—including PhaP1 , a phasin family protein that affects PHB production, and PhbA1 , an acetyl-CoA acetyltransferase— decreased root colonization. The importance of PHB metabolism in bacteria during plant root colonization was reported previously in studies of Setaria-Herbaspirillum and legumerhizobium symbiosis .To more definitively test the importance of individual genes identified in our screen, we selected candidate genes and created insertion mutations in 15 separate genes. These genes were selected to cover a diversity of putative functions representing operons containing multiple genes, as well as single genes, including those associated with both positive and negative fitness scores . Using a gnotobiotic system, a competitive colonization assay was performed in which colonization of S. viridis roots by the individual mutants was measured, as well as their ability to compete for colonization when coinoculated with the corresponding wild-type strain. Since root colonization is a dynamic process and might change over time, we evaluated competition at three different time points. For A. olearius DQS4T , we selected six genes where mutations reduced colonization, specifically a transcriptional regulator, ybeZ, ketoacyl ACP synthase , peaF, pcm, and purU . Mutants defective in genes that resulted in reduced colonization in competition with the wild-type strain showed delayed colonization of Setaria roots. Mutation of the transcriptional regulator gene represents the most extreme case where colonization was completely blocked when inoculated singly onto Setaria roots . This gene encodes an AphS protein known to be involved in the phenol degradation pathway, where phenol is converted into catechol via catechol 2,3-dioxygenase . Analysis of A. olearius DQS4T and BH72 genomes showed two that is produced by the wild type that can compensate for its loss in the mutant. As for the other mutants that impaired A. olearius DQS4T colonization ybeZ, ketoacyl ACP synthase , peaF, pcm, and purU, all showed a significant reduction in colonization that was most pronounced 3 and 5 days after inoculation both when inoculated individually or in competition with the wild-type strain .