Analysis of the mucR gene regulating biosynthesis of exopolysaccharides: implications for biofilm formation in Sinorhizobium meliloti Rm1021
Abstract
Bacterial surface polysaccharides are crucial for establishment of successful rhizobia-legume symbiosis, and in most bacteria, are also critical for biofilm formation and surface colonization. In Sinorhizobium meliloti, the regulatory protein MucR controls exopolysaccharide production. To clarify the relationship between exopolysaccharide synthesis and biofilm formation, we studied mucR expression under growth conditions that influence attachment to polyvinylchloride, developed a microtiter plate assay to quantify biofilm formation in S. meliloti strain Rm1021 and mutants defective in succinoglycan (EPS I) and/or galactoglucan (EPS II) production, and analyzed expression of EPS I and EPS II genes by quantitative reverse transcriptase-PCR. Consistent with previous studies of planktonic bacteria, we found that disruption of the mucR gene in Rm1021 biofilms increased EPS II, but reduced EPS I gene expression. mucR expression was not affected by environmental conditions that influence biofilm formation on polyvinylchloride, and biofilm formation by Rm1021 was independent of exopolysaccharide synthesis. Other factors on the Rm1021 cell surface, and growth conditions, presumably regulate attachment and/or growth as a biofilm on polyv...Continue Reading
References
Citations
Related Concepts
Related Feeds
Biofilm & Infectious Disease
Biofilm formation is a key virulence factor for a wide range of microorganisms that cause chronic infections.Here is the latest research on biofilm and infectious diseases.
Biofilms
Biofilms are adherent bacterial communities embedded in a polymer matrix and can cause persistent human infections that are highly resistant to antibiotics. Discover the latest research on Biofilms here.