Streptomyces CS57 균주로부터 신규 Phospholipase D의 생산 분리정제 및 특성분석

Abstract

Soil samples were screened for actinomyces strains capable of producing phospholipase D, and a strain, Streptomyces CS57, showing phosphlipase D activity was isolated. Streptomyces SC57 produced the highest phospholipase D when grown in GYT medium(glucose 2%, Yeast extract 1.5%, tryptone 0.5%, calcium carbonate 0.1%) at 28℃. Analysis of the 16S rDNA showed that the strain CS57 was highly homologous to Streptomyces indonesiensis DSM41759 and Streptomyces griseocarneus DSM40004. One form of extracellular phospholipase D was purified through ammonium sulfate fractionation, heat treatment, ultramembrane(YM10) filtration, Sepharose Cl-6B column chromatography, DEAE-Sepharose Cl-6B column chromatography, Sephadex G-75, and CM sephadex C50 column chromatography, which produced a major band of 34kDa on a 12% SDS-PAGE. The optimal temperature for hydrolytic activity was 55℃. About 80% of the enzyme activity remained after being treated at 50℃ for 1 hour. The enzyme showed an optimal pH of 6.5 in hydrolytic reaction and was stable between pH 5-8. Triton X-100 increased enzyme activity, but actvity of enzyme was inhibited by Tween 20 and Tween 80.