The possibilities of changing the production of exocellular polysaccharides of a mutant Mycobacterium strain.

By second-step mutagenesis and treatment with N-methyl-N'-nitro-N-nitrosoguanidine a mutant strain of Mycobacterium sp. V-649 producing a glucan extracellular polymer and another new streptomycin-resistant mutant were prepared. This mutant strain formed more than 100% first-rate (1.0-1.2%) exocellular polysaccharide. Treatment with 1% dimethyl sulfoxide during submerged cultivation of the mutant strain did not increase the production of the extracellular polysaccharide.