Optimal Culture Conditions for Production of Subtilisin-like Protease Inhibitor from Streptomyces thermocarboxydus C12

The objective of this paper was to investigate optimal culture conditions for the production of an inhibitor against subtilisin-like protease from Streptomyces thermocarboxydus (S. thermocarboxydus) C12 isolated from sediments of Gwangyang coast. The optimal temperature and initial pH for the production of subtilisin-like protease inhibitor were $40^{\circ}C$ and pH 8.0, respectively. Inhibition activities were high for galactose, glucose and fructose. The best carbon source and its concentration were galactose and 1.6% (w/v), respectively. Inhibition activities were also high in medium containing polypeptone, proteose and peptone. Optimal nitrogen source and concentration were protease peptone and 0.5% (w/v), respectively. Optimal concentrations for inhibitor production were 1% (w/v) for NaCl and 1 mM LiCl for metal salts. The subtilisin-like protease inhibitor from S. thermocarboxydus C12 showed a maximum inhibitor activity after cultivation for 84 h under the optimized medium.

Streptomyces thermocarboxydus C12에서 Subtilisin-like Protease Inhibitor 생산을 위한 최적배양조건

광양만의 해안 뻘에서 protease 저해력이 우수한 균주 S. thermocarboxydus C12를 분리하여 최적의 저해제 생산 조건을 조사하였다. 최대 저해활성을 보이는 온도와 초기 pH는 각각 $40^{\circ}C$와 8.0이었다. 저해제 생산에 미치는 탄소원의 영향을 검토한 결과, 단당류인 galactose, glucose, fructose와 다당류인 starch에서 높은 저해활성을 보였으며, 최적의 탄소원과 농도는 각각 galactose와 1.6%(w/v)였다. 질소원의 경우 복합배지인 polypeptone과 proteose peptone에서 가장 높은 저해활성이 나타났으며, 최적의 농도와 질소원은 0.5%(w/v)와 proteose peptone이었다. 최적의 NaCl 농도와 금속이온은 각각 1%(w/v)와 1 mM LiCl이었다. 선정된 최적배양조건에서 균주를 배양한 결과, 84시간 동안 배양 시 저해활성이 최대인 것으로 나타났다.