MYXOBACTERIAL INTERACTION WITH PHIZOBIA

Abstract

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.