The predation of four soil myxobacteria - Myxococcus fulvus, “yxococcus
virescens, Myxococcus stipitatus and Polyangium fuscum on several susceptible
Rhizobium spp. was investiqated. No significant difference in
the course of attack on living and heat killed rhizobial cells was seen
in plate assays, but viable cells were resistant to the myxobacterial
culture filtrate in tube assays.
Some partially lysis-resistant rhizobia were rendered more susceptible
when separated from their polysaccharide. On hydrolysis, the purified
gum gave glucose, galactose, mannose and glucuronic acid; aminosugars
were absent. This qum had no effect on the synthesis and activity of lytive.
The partially purified lytic enzyme complex showed an N-acetyl
hexosaminidase activity on purified Rhizobium leguminosarum cell walls.
Viable cells, polysaccharide gum, purified cell walls and lipids ofR.
leguminosarum did not induce any chemotactic response in any of the
myxobacters tested, while autoclaved cells and cell proteins attracted
the migrating cells.
These myxobacters were also found in the rhizosphere of several local
legumes. When introduced in sterilized soil with added rhizobia,
M. fulvus and P. fuscum suppresses root nodulation
