Formation of exopolysaccharides by Rhodococcus erythropolis and partial characterization of a heteropolysaccharide of high molecular weight

Abstract

Polysaccharide formation by Rhodococcus erythropolis was studied using lower mono-, di-and trihydric alcohols, sugars and n-alkanes as carbon sources. Cultural conditions of the organism were examined with regard to polysaccharide production. It was demonstrated that a glycerol substrate, an 30°C incubation temperature and a pH of 7.5 were optimal cultural conditions for polysaccharide formation. Addition of penicillin G in the decelerating growth phase increased the polysaccharide concentration in the culture filtrate to 3.1 g/l. One of the main extracellular heteropolysaccharides formed by Rhodococcus erythropolis consisted of glucose and mannose in the molar ratio 1∶1, a small portion of protein and a trace of glucosamine. The molecular weight was to be 1·14×106.