Bacteria epiphytic

The phyllosphere (or aerial) parts of plants represent a challenge for the survival of microbes. The exposure to high doses of UV, fluctuations in temperature, and relative humidity all compromise viability (Heaton and Jones, 2008 Whipps et ah, 2008). Bacteria (epiphytes) that exist within the phyllosphere have evolved specialized mechanisms to improve stress tolerance and nutrient acquisition. Pseudomonas spp. form the predominant bacterial population recovered on the leaves of plants (Brandi and Amundson, 2008 Lindow and Brandi, 2003). Epiphytic pseudomonad s produce fluorescent or pigmented compounds that afford protection to UV. 

Endophytic bacteria can colonize plant tissues without bringing about adverse effects on the plant, in contrast to epiphytes that remain in the external environment. Bacteria with the established potential for degradation have been used to improve the tolerance and degradation of contaminants ... 

S. E. Lindow, Methods of preventing frost injury caused by epiphytic ice-nucle-ation-active bacteria. Plant Disease March ill (1983). 

That the oxidative burst is directly involved in the chemical defense of these algae is clear. This reaction can be inhibited by diphenyleneiodonium, a suicide inhibitor of NADPH-oxidase which suppresses both the production of reactive oxygen species and the natural resistance to epiphytic bacteria. In addition a role in the defense against endophytes was indicated, since pre-treatment with oligomeric guluronates resulted in decreased infection of L. digitata with the pathogen Laminariocolax tomentosoides [141]. 

Sublethal (actual exposure concentration and duration unknown) Growth stimulation (from reduced competition by aufwuchs, bacteria, and epiphytic algae) 5... 

Boyd KG, Adams DR, Burgess JG (1999) Antibacterial and repellent activities of marine bacteria associated with algal surfaces. Biofouling 14 227-236 Cebrian J, Enriquez S, Fortes M, AgawinN, Vermaat JE, Duarte CM (1999) Epiphyte accrual on Posidonia oceanica (L.) Delile leaves implications for light absorption. Bot Mar 42 123-128... 

In wetlands N2 fixation can occur in the water colnmn, in the aerobic water-soil interface, in the anaerobic soil bulk, in the rhizosphere, and on the leaves and stems of plants. Phototrophic bacteria in the water and at the water-soil interface are generally more important than non-photosynthetic, heterotrophic bacteria in the soil and on plant roots (Buresh et al, 1980 Roger 1996). The phototrophs comprise bacteria that are epiphytic on plants and cyanobacteria that are both free-living and epiphytic. A particularly favourable site for cyanobacteria is below the leaf surface of the water fern Azolla, which forms a very efficient symbiosis with the cyanobacterinm Anabaena azollae. This symbiosis and those in various leguminous plants have been exploited in traditional rice prodnction systems to sustain yields of 2 to 4 t ha of grain withont fertilizer for hnndreds of years. 

The results of the axenlc culture experiments Indicate that bacteria may play an important role In the growth of epiphytic... 

Cooley, M. B., Chao, D., and Mandrell, R. E. (2006). Escherichia coli 0157 H7 survival and growth on lettuce is altered by the presence of epiphytic bacteria. J. Food Prot. 69, 2329-2335. 

Because of the high area of solid surfaces covered with biofilms, these biofilms dominate the heterotrophic metabolism in many aquatic ecosystems. In streams, rivers, and shallow lakes, bacterial activity in epilithic and epiphytic biofilms may be several times higher on an areal basis than the activity of free living bacteria. By the differential use of specific DOM fractions, biofilm bacteria influence the biogeochemical composition of DOM in these ecosystems. Biofilms thus can control biogeochemical fluxes of DOM and are important sinks of organic matter. 

Theil-Nielsen, J., and M. Sondergaard. 1999. Production of epiphytic bacteria and bacterio-plankton in three shallow lakes. OIKOS 86 283—292. 

Dissemination of applied INA deletion mutants. In its assessment, EPA scientists assumed that, given the nature of the proposed experiments and the ecological characteristics of epiphytic bacteria such as those to be applied, the INA bacteria could not be contained within the boundaries of the test plot. However, field studies conducted with the INA+ parental strains suggested that dispersal of the applied bacteria from the test site would probably be minimal. 

Competitiveness of INA deletion mutants. Greenhouse tests had been conducted to evaluate the competitiveness of the INA strains compared to their naturally occurring parental strains as well as other epiphytic strains. Results indicated that the INA strains are competitive equals with naturally occurring NON-INA and INA+ strains. Application of equally low or high dosages of INA+ and INA bacteria resulted in co-existance without either population predominating. When unequal dosages... 

Long chain fatty aldehydes such as (Z)-8-heptadecenal, (Z, Z)-8, 11-heptadeca-dienal and (Z, Z, Z)-8,11,14-heptadecatrienal have been identified as major volatile compounds in the Ulvaceae essential oils (4). They have been shown to be produced enzymatically from unsaturated fatty acids in the field fronds of U. pertusa collected from the sea (20,29). Thus, it remained to establish unequivocally that the enzymatic activity does not derive from the attached bacteria or other epiphytes. 

Examination of the thalli culture on ST3ss and M23 media showed the culture was free of bacteria and epiphytes. Thus, the unsaturated Cn-i-aldehydes are produced from Cn-fatty acids by algal enzymes and not by the enzymes of associated organisms... 

The idea that exopolysaccharides (EPS) produced by several plant pathogenic bacteria could be involved in the pathogenic processes and or/the saprophytic or epiphytic phases of the life cycle appears to be generally accepted. Copious EPS production is often associated with increased virulence [89]. It is conceivable that the EPSs prevent bacterial elicitors of host-defence responses from reaching the plant and may inhibit deleterious adherence during infection, thus "maintaining (in both cases) a compatible interaction" [89],... 

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