[The effect of the carbohydrate components of pea roots on the enzymatic activity of the surface agglutinins of Rhizobium leguminosarum bv. viciae 252].

The interaction of the surface agglutinins of Rhizobium leguminosarum by. viciae 252 with the carbohydrate components of host pea roots alters the beta-glucosidase and proteolytic activities of the agglutinins.

[Functional activity of exoglycans from Rhizobium leguminosarum bv. viciae 250a and its nitrogen-resistant mutant M-71 during the formation of legume-rhizobia symbiosis against a high-nitrogen background].

The functional activity of the exoglycan complex (EGC) polysaccharides from Rhizobium leguminosarum bv. viciae 250a and its nitrogen-resistant mutant M-71 capable of inducing the formation of nitrogen-fixing nodules on pea roots against a high-nitrogen background (4.8 mM NO3-) was studied in vegetation tests.

[Investigation of lipopolysaccharides from Sinorhizobium meliloti SKHM1-188 and two of its mutants with decreased nodulation competitiveness].

A comparative study of the lipopolysaccharides (LPS) isolated from Sinorhizobium meliloti SKHM 1-188 and two its LPS-mutants (Th29 and Ts22) with sharply decreased nodulation competitiveness was conducted. Polyacrylamide gel electrophoresis with sodium dodecyl sulfate revealed two forms of LPS in all the three strains: a higher molecular-weight LPS1, containing O-polysaccharide (O-PS), and a and lower molecular-weight LPS2 without O-PS. However, the LPS1 content in mutants was significantly smaller than in the parent strain.

[The influence of lipopolysaccharides and glucans from two Rhizobium leguminosarum bv. viciae strains on the formation and efficiency of their symbioses with pea plants].

The influence of lipopolysaccharides (LPS), glucans, and their unseparated complexes on nodulation activity of rhizobia and efficiency of their symbioses with pea plants was studied in vegetation experiments. Two Rhizobium leguminosarum bv. viciae strains which differed in their symbiotic properties were used: strain 31 (fix+, efficient, moderately virulent, moderately competitive), and strain 248b (fix-, inefficient, highly virulent, highly competitive).

[The biological activity of the Sinorhizobium meliloti glucan].

The study of the effect of the periplasmic glucan isolated from the root-nodule bacterium S. meliloti CXM1-188 on the symbiosis of another strain (441) of the same root-nodule bacterium with alfalfa plants showed that this effect depends on the treatment procedure. The pretreatment of alfalfa seedlings with the glucan followed by their bacterization with S.