Bacillus 속(屬)균에 의한 균체외(菌體外) 단백질의 생산에 대하여

Studies on the Extracellular Protein Production by Bacillus sp.

토양으로부터 균체외(菌體外) 단백질 생산균주 17주(株)를 분리하여 이 중 단백질생산이 강한 T219를 선정하여 동정(同定)하였으며 단백질 생산에 영향을 미치는 인자(因子)들을 검토하였다. T219균주(菌株)는 Bacillus속으로 동정(同定)되였으며 균체외(菌體外) 단백질생산 최적온도는 $25^{\circ}C$, pH는 7.5이었다. 단백질생산균주들이 분비하는 단백질에서는 protease와 amylase활성은 보이지 않았으며, 배양시간에 따른 단백질생산은 배양 2일에서 최대로 되었다. yeast extract와 meat extract를 함유한 배지에서 균체증식은 컸지만, 단백질 축적은 거의 없었고, polypeptone은 균체(菌體) 증식과 단백질생산에 큰 효과를 보였다. 또한 배지에 glycine과 L-isoleucine을 혼합하여 첨가하였을때 단백질생산의 효과가 커서 4mg/ml의 단백질축적이 있었다. T219균주(菌株)는 streptemycin의 $30{\mu}g/ml$이상의 농도에서 생육이 저해되었고, EDTA의 5mM농도에서는 생육에 영향을 받지 않았다. 또한, 이들 물질은 단백질생산에 영향을 미치지 않았다.

Seventeen extracellular protein producing bacteria were isolated from soil samples, among which T219 strain having a strong capability of producing the protein was selected and identified for investigation of biological characteristics. The factors which affect the protein production were investigated and the results are summarized as follows. T219 strain which produces the most extracellular protein was identified as Bacillus sp. Optimum temperature and pH for production of the extracellular protein by T219 strain were $25^{\circ}C$ and 7.5 respectively. Almost no activities of protease and amylase were observed in the protein produced by the protein producing bacteria. In the medium containing yeast extract, the cell growth was moderately high, but almost no accumulation of protein was observed. However, polypeptone had significant effects on both the cell growth and the protein accumulation. The addition of glycine and L-isoleucine to the medium containing polypeptone, yeast extract and meat extract had a great effect on the protein production; 4mg/ml of protein accumulation was observed.