• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.373-378
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• 2008

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.

• Journal of Life Science
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• v.18 no.4
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• pp.482-487
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• 2008

In this study, we screened and identified the bacterial strain showing high alkaline pretense inhibitor activity from marine environment. Nine bacterial strains with alkaline pretense inhibitor activity were isolated from marine sediments. Among them, strain C12 had the highest alkaline pretense inhibitor activity and was selected for further taxonomical study. On the basis of morphological and physiological characteristics, strain C12 was identified as the genus Streptomyces. A phylogenetic analysis of the 165 rDNA showed that the isolated strain was actually a member of the genus Streptomyces, because the determined sequence exhibited a higher homology with Streptomyces thermocarboxydus. Morphological characteristics showed cylindrical spore chain and smooth spore surface by scanning electron microscope. Strain C12 was grown on all media except for ISP 9 agar. This strain could be grown in the medium containing up to 9% NaCl.