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A mutant strain (39E H8) of Thermoanaerobacter ethanolicus that displayed high (8% [vol/vol]) ethanol tolerance for growth was developed and characterized in comparison to the wild-type strain (39E), which lacks alcohol tolerance (<1.5% [vol/vol]). The mutant strain, unlike the wild type, lacked primary alcohol dehydrogenase and was able to increase the(More)
Proton nuclear magnetic resonance (1H NMR) and fast atom bombardment mass spectrometric analyses were performed on enzymatically derived oligosaccharides from the acidic excreted polysaccharides (EPS) from representative bacterial strains of the pea-nodulating symbiont, Rhizobium leguminosarum (128C53, 128C63, and 300) and the clover-nodulating symbiont,(More)
A polysaccharide depolymerase isolated from the phage lysate of Rhizobium trifolii 4S was used to fragment capsular polysaccharides (CPS) and extracellular polysaccharides (EPS) of R. trifolii 0403 into oligosaccharides. These products were analyzed for clover lectin (trifoliin A)-binding ability, effect on infection of white clover root hairs, and changes(More)
exo mutants of Rhizobium meliloti SU47, which fail to secrete acidic extracellular polysaccharide (EPS), induce Fix- nodules on alfalfa. However, mutants of R. meliloti Rm41 carrying the same exo lesions induce normal Fix+ nodules. We show that such induction is due to a gene from strain Rm41, which we call lpsZ+, that is missing in strain SU47. lpsZ+ does(More)
Acidic heteropolysaccharide lyases from lysates of phages 4S and BY15 grown on Rhizobium trifolii 4S and R. trifolii 0403, respectively, were used to analyze the capsular and excreted extracellular acidic polysaccharides of R. trifolii 0403. The activities of the enzymes as measured by viscometry were enhanced by the addition of calcium. The oligosaccharide(More)
The general view on Rhizobium chitolipooligosaccharides (CLOS) is that they are made in very low levels as diffusible molecules and are primarily secreted by the bacteria into the extracellular milieu where they interact with the host. However, the structural and predicted physicochemical properties of these amphiphilic molecules led us to postulate that(More)
Rhizobium chitolipooligosaccharides (CLOSs) are heterogeneous fatty acylated N-acetyl glucosamine oligomers with variations in both the polar (hydrophilic) oligosaccharide head group and the non-polar (hydrophobic) fatty acyl chain. They trigger root hair deformation and cortical cell divisions in legume roots during development of the nitrogen-fixing(More)
A second core oligosaccharide fragment has been isolated and characterized from the lipopolysaccharide (LPS) of Rhizobium trifolii ANU 843. The oligosaccharide is a tetrasaccharide composed of galactose, galacturonic acid, mannose, and 3-deoxy-D-manno-2-octulosonic acid. The mannose residue is alpha-linked to the 4-position of 3-deoxy-D-manno-2-octulosonic(More)
Host specificity in the Rhizobium-legume symbiosis is controlled in the bacterium by host specific nodulation (hsn) genes residing on its symbiotic plasmid. We have examined the structure of the major acidic heteropolysaccharide produced by recombinant hybrid strains of Rhizobium leguminosarum carrying cloned R. trifolii hsn genes with those produced by the(More)
A new hydroxylated, very long-chain fatty acid has been isolated and characterized from the lipopolysaccharide (LPS) of Rhizobium trifolii ANU 843. The lipid A of the organism was degraded by mild alkali and borohydride and the products methylated, peracetylated, and fractionated on a C18 reverse-phase column. The major lipid fraction was reduced with(More)