(Genetics and biochemistry of Rhizobium meliloti acidic extracellular heteropolysaccharide and its role in nodulation): Final technical report

Technical Report · Sun Jan 01 00:00:00 EST 1989

OSTI ID:5620956

Leigh, J A

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
• Resource Relation: Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
59 BASIC BIOLOGICAL SCIENCES
POLYSACCHARIDES
BIOLOGICAL FUNCTIONS
RHIZOBIUM
MOLECULAR BIOLOGY
GENE MUTATIONS
PROGRESS REPORT
SUCCINIC ACID
BACTERIA
CARBOHYDRATES
CARBOXYLIC ACIDS
DICARBOXYLIC ACIDS
DOCUMENT TYPES
FUNCTIONS
MICROORGANISMS
MUTATIONS
ORGANIC ACIDS
ORGANIC COMPOUNDS
SACCHARIDES
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