한국재래식간장에서 분리한 특향생성 Bacillus sp.의 NTG 변이주를 모균주로하여 자외선에 의해 2차 돌연변이시킴으로써 amylase, protease의 생산성이 증강된 우량간장 발효균주를 개발할 수 있었다. 변이주는 모균주에 비해 amylase의 경우 58%, protease의 경우 41% 정도 증강시킬 수 있었으며 그 생성효소들은 최적반응 pH, 최적반응온도 등 효소학적 특성이 거의 유사하였다. 5M의 고농도 식염용액에서도 그 작용이 크게 저하되지 않았으며 효소생산농도 2M정도까지는 별다른 영향을 받지 않았다.
A mutant for Korean soy sauce which wilt improve the productivity of amylase and protease was obtained through the second mutation of the original strain using UV radiation. The original strain was the NTG treated mutant of the Bacillus sp. producing peculiar flavour which had been isolated from the korean soy sauce. The mutant could improve the productivity of amylase by 58% and that of protease by 41%. The enzyme produced in this way were similar in enzymatic properties such as optimal reaction pH and temperature. The reaction was not deterred by highly densed salt solution of 5 M and the enzyme productivity was not influenced in the concentration of up to 2 M.
