Osmoregulated Periplasmic Glucans (OPGs), Alginate, and Biofilm Formation in Pseudomonas syringae
Alejandro Penaloza-Vazquez, Christina M. Baker and Carol L. Bender
from: Bacterial Polysaccharides: Current Innovations and Future Trends (Edited by: Matthias Ullrich). Caister Academic Press, U.K. (2009)
In recent years it became increasingly clear that the cell envelope, loosly attached, or tightly fixed exopolymeric substances might play an important role for plant pathogenic bacteria such as Pseudomonas syringae. Herein, the role and synthesis of the osmoregulated periplasic glucans (OPGs) in P. syringae are described in detail. OPGs are produced by many proteobacteria, and are important for the bacterial envelope and bacterial-host interactions. Mutants defective in production of OPGs in P. syringae exhibit a pleiotropic phenotype including the overproduction of the exopolysaccharide (EPS) alginate, decrease in cell viability under low osmolarity, low epiphytic fitness on leaves, and are unable to form biofilms on plant leaves. Results for the plant pathogen are compared to those for the opportunistic human pathogen, P. aeruginosa. In addition, we discussed the possibility of molecular interactions between OPGs production, the physical integrity of the membrane, and the associated EPS regulatory systems read more ...