Abstract
Four polyglutamate (PGA)-producing Bacillus strains were isolated from "thua nao" in Thailand. Three of these did not require biotin for growth. All four produced high activities of γ-glutamyltranspeptidase (γ-GTP). Each of these strains carried a single plasmid species, and their molecular weights andd restriction patterns differ overall. The "thua nao" plasmids were found to be strongly hybridized with the "natto" plasmid, pUHl, which encodes the γ-GTP gene responsible for PGA production in B. subtilis (natto). Most of the generated fragments with HindIII from these plasmids showed higher degrees of homology with the probe, but some did not. Apparently a "natto" plasmid is distributed widely in PGA- producing Bacillus strains may develop from a common ancestral molecule. Therefore, the distribution of "natto" plasmids in PGA-producing Bacillus strains may help to distinguish B. subtilis from B. subtilis (natto).
