OmpR in most model organisms is responsive to osmotic stress

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.