[Comparative analysis of 2 Bacillus polymyxa strains differing in the spectrum of exogenous polysaccharides produced].

The characteristic features of the development of 2 Bacillus polymyxa strains differing in the spectrum of the produced extracellular heteropolysaccharides were compared. The strains were grown on solid media and under submerged conditions. Electron microscopy revealed marked differences in the ultrastructure of the developing cultures. It was noted that the mutant variant B formed a vigorous fibrillar and capsular layer of the polysaccharide nature strictly oriented in the space perpendicularly to the cell surface. Changes in the mutant growth processes were characterized by a lower growth rate of the cell population. In the process of growth the initial culture did not form structured capsules and was lysogenic. Pronounced differences in the proteolytic activity were indicative of a definite interrelation between sporulation of the strains and activity of their exoproteases. The regularities of the development of the mutant strain of B. polymyxa allowed one to define the fundamental approaches to development of optimal cultivation conditions for the organism producing extracellular polysaccharides.