Regulation of polyglutamate production in Bacillus subtilis (natto): Transformation of high PGA productivity.

Bacillus subtilis (natto) produces a considerable amount of polyglutamate (PGA). The genetic character of high PGA productivity of B. subtilis (natto) was transferred by DNA-mediated transformation to B. subtilis Marburg 168 which cannot produce PGA. The enzyme activity of γ-glutamyltranspeptidase (γ-GTP) of the three transformants, 3F1, Fl-9 and M5B4, was 124, 233 and 147 mU/ml, which is about 25, 250 and 100% of that of the donor strains, respectively. However, other enzyme activities such as those of alanine racemase or transammase among the parental strains and representative transformants were almost the same. These results suggested that γ-GTP activity might mainly participate in the biosynthesis of PGA in B. subtilis (natto).