Environmental Regulation of Exopolysaccharide Production in Sinorhizobium meliloti
نویسندگان
چکیده
منابع مشابه
Environmental regulation of exopolysaccharide production in Sinorhizobium meliloti.
Exopolysaccharide production by Sinorhizobium meliloti is required for invasion of root nodules on alfalfa and successful establishment of a nitrogen-fixing symbiosis between the two partners. S. meliloti wild-type strain Rm1021 requires production of either succinoglycan, a polymer of repeating octasaccharide subunits, or EPS II, an exopolysaccharide of repeating dimer subunits. The reason for...
متن کاملRole of Specific Quorum-Sensing Signals in the Regulation of Exopolysaccharide II Production within Sinorhizobium meliloti Spreading Colonies
BACKGROUND Quorum sensing (QS) in Sinorhizobium meliloti involves at least half a dozen different N-acyl homoserine lactone (AHL) signals. These signals are produced by SinI, the sole AHL synthase in S. meliloti Rm8530. The sinI gene is regulated by two LuxR-type transcriptional regulators, SinR and ExpR. Mutations in sinI, sinR and expR abolish the production of exopolysaccharide II (EPS II). ...
متن کاملSinorhizobium meliloti SyrA mediates the transcriptional regulation of genes involved in lipopolysaccharide sulfation and exopolysaccharide biosynthesis.
Sinorhizobium meliloti is a gram-negative soil bacterium found either in free-living form or as a nitrogen-fixing endosymbiont of leguminous plants such as Medicago sativa (alfalfa). S. meliloti synthesizes an unusual sulfate-modified form of lipopolysaccharide (LPS). A recent study reported the identification of a gene, lpsS, which encodes an LPS sulfotransferase activity in S. meliloti. Mutan...
متن کاملSurvival and exopolysaccharide production in Sinorhizobium meliloti WSM419 are affected by calcium and low pH.
Cells of Sinorhizobium meliloti WSM419 showed an adaptive acid-tolerance response when grown at pH 5.8 instead of pH 7.0. Increasing concentrations of calcium in the exposure medium significantly decreased the death rate of WSM419 cells under conditions of acid stress (pH 4.0). The effect of calcium on survival at pH 4.0 however, appears unconnected to exopolysaccharide (EPS), since a strain wi...
متن کاملRegulation of succinoglycan and galactoglucan biosynthesis in Sinorhizobium meliloti.
Sinorhizobium meliloti (Rhizobium meliloti) 2011 has the ability to produce the two acidic exopolysaccharides succinoglycan (EPS I) and galactoglucan (EPS II). EPS I is a branched heteropolysaccharide composed of octasaccharide repeating units, whereas EPS II is a linear heteropolysaccharide consisting of disaccharide subunits. The exo-exs and exp gene clusters are involved in the biosynthesis ...
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ژورنال
عنوان ژورنال: Journal of Bacteriology
سال: 2000
ISSN: 0021-9193,1098-5530
DOI: 10.1128/jb.182.3.599-606.2000