Production of Glucoamylase from Hybrid Constructed by Intergenic Nuclear Transfer between Saccharomycopsis sp. and Saccharomyces sp.

핵전이법에 의해 형성된 Saccharomycopsis 속과 Saccharomyces 속의 잡종에서 glucoamylase 생산에 관한 연구

The glucoamylase was purified from the induced culture filtrate of hybrid between Saccharomycopsis sp. and Saccharomycopsis sp. made by nuclear transfer and characterized for some enzyme properties. The enzymewas purified 76-fold in an overall yield of 16% from the culture medium by ammonium sulfate fractionation,Sephadex G-150 gel permeation chromatography and DEAE-Sephadex A-50 ion exchage chromatography.The molecular weight of the purified glucoamylase was estimated to be 57.5 KDa on SDS-polyacrylamidegel electrophoresis and Sephadex G-150 gel permeation chromatography. The purified enzyme was active atpH-5.0 and $40^{\circ}C$. The Km value for soluble starch was 2.6 mg/ml. The enzymatic activity was stimulated inthe presence of TEX>$Ca^{2+}$, EDTA, $Co^{2+}$, $Mg^{2+}$, and $Mn^{2+}$

핵전이에 의해 형성된 잡종의 유도 배양액으로부터 glucoamylase를 정제하고 몇몇의 효소 특성을 조사하였다. 효소는 76배 정제하였고, ammonium sulfate fractionation, Sephadex G-150 gel permeation chromatography 그리고 DEAE-Sephadex A-50 ion exchange chromatography의 순서 배양액으로부터 정제한 결과 전반적인 수율은 16%를 나타내었다. SDS-polyacrylamide gel electrophoresis와 Sephadex G-150 gel permeation chromatography에 의하여 정제된 glucoamylase의 분자량을 측정한 결과 57.5 kDa를 나타내었으며, 정제된 효소의 최적 pH와 온도는 각각 5.0과 $40^{\circ}C$로 나타났다. 또한 가용성 전분에 대한 Km값은 2.6 mg/ml을 나타내었으며, 정제된 효소는 $Ca^{2+}$, EDTA, $Co^{2+}$, $Mg^{2+}$, 그리고 $Mn^{2+}$의 존재하에 활성이 중진됨을 알수 있었다.