Influences of Culture Medium Components on the Production Poly (γ-Glutamic Acid) by Bacillus subtilis GS-2 Isolated Chungkookjang

Abstract

국문요약Poly-γ-glutamic Acid(γ-PGA)를 다량 생산하는 균주를 우리나라의 전통발효식품인 청국장으로부터 Bacillus subtilis GS-2를 분리하였다. 이 균은 glutamic acid 의존형 균으로, 이 균에 의한 γ-PGA 생산 최적 조건을 검토한 바, 단순배 지(L-glutamic acid 2.0%, glucose 1.0%, NH4Cl 0.5%, KH2PO4 0.05%, MgSO4․7H2O 0.01%, pH 7.0)로 진탕배양(220 rpm) 하였을 때, 배양시간 48시간, 최적온도 33℃, 그리고 초기 pH 6.5로 나타났다. 영양원으로 glutamic acid 3%, sucrose 3%, NH4Cl 0.25%, KH2PO4 0.15%, MgSO4․7H2O 0.015%에서 γ-PGA 최대 생산량이 31.0 g/ℓ이었다.

Factors increasing poly-γ-glutamic acid content of cheongguk-jang fermented by Bacillus subtilis 168

“…By the way in the presence of added citric acid, Bacillus subtilis CCTCC202048 produced the highest amount of c-PGA (54.21 g/kg dry weight) in solid-state fermentation of mixture of soybean cake and wheat bran (Jian et al, 2005). Bacillus subtilis GS-2 produced the highest amount of c-PGA (16.76 g/L) in media containing 3.0%(w/w) sucrose (Bang et al, 2012). Bacillus methylotrophicus SK19.001 showed a c-PGA production rate of 14 g/L by 3%(w/w) glycerol (Peng et al, 2015).…”