(Genetics and biochemistry of Rhizobium meliloti acidic extracellular heteropolysaccharide and its role in nodulation): Final technical report
We have been working with two polysaccharides secreted by Rhizobium meliloti that promote nodule invasion, succinoglycan and EPSb. R. meliloti mutants in succinoglycan synthesis are designated Exo-, and fail to invade alfalfa root nodules. Multiple forms of succinoglycan are produced by R. meliloti, and this raises the question, which form is involved in nodule invasion We observed that a low molecular weight oligosaccharide form is secreted by wild type R. meliloti as well as the high molecular weight polymer. The oligosaccharide, in turn, also has multiple forms. Recently we have found that multiple subfractions of the oligosaccharide are secreted that apparently differ in size. Although these fractions appeared identical by proton NMR spectroscopy, they migrated in at least three distinct fractions in anion exchange chromatography. Also, in a EPLC sizing system we have recently begun using, we observed distinct low molecular weight fractions. We are currently collaborating with Steve Levery and S. Hakomori of the Biomembrane Institute, Seattle, to measure the molecular weights of these fractions by mass spectrometry. One likely outcome is that the fractions represent one, two, three, and possibly greater numbers of subunits of succinoglycan. Recently we determined that the ratios of total sugar constituents to reducing ends is consistent with this interpretation.
- Research Organization:
- Washington Univ., Seattle, WA (USA). Dept. of Microbiology and Immunology
- DOE Contract Number:
- FG06-86ER13532
- OSTI ID:
- 5620956
- Report Number(s):
- DOE/ER/13532-3; ON: DE89017812
- Country of Publication:
- United States
- Language:
- English
Similar Records
A second exopolysaccharide of Rhizobium meliloti strain SU47 that can function in root nodule invasion
Genetics and biochemistry of the Rhizobium meliloti acidic extracellular heteropolysaccharide and its role in nodulation: Annual report for the period 1 June 1987-31 May 1988
Related Subjects
140504* -- Solar Energy Conversion-- Biomass Production & Conversion-- (-1989)
550200 -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
BIOLOGICAL FUNCTIONS
CARBOHYDRATES
CARBOXYLIC ACIDS
DICARBOXYLIC ACIDS
DOCUMENT TYPES
FUNCTIONS
GENE MUTATIONS
MICROORGANISMS
MOLECULAR BIOLOGY
MUTATIONS
ORGANIC ACIDS
ORGANIC COMPOUNDS
POLYSACCHARIDES
PROGRESS REPORT
RHIZOBIUM
SACCHARIDES
SUCCINIC ACID