Isolation of two strains (S-R type) of Bacillus circulans and purification of a cyclomaltodextrin-glucanotransferase.

From wild type inoculum of Bacillus circulans DF 9 which produce cyclomaltodextrin-glucanotransferase (EC 2.4.1.19, CGTase), two different kinds of colonies were isolated, which correspond to the classical S-R variation. From the culture medium of both colonies grown together a CGTase was purified about 50 fold with a yield of 54% in two steps. From pure R-cell culture the enzyme was purified by about 38 folds with a yield of 79% in only one step, showing a complete homogeneity as judged by a native PAGE analysis.