논문 상세보기
pp.69-75
B. thuringiensis subsp. kurstaki HD-1을 아밀라제 생산배지에 32℃로 24시간 배양하였을 때 아밀라제 활성은 0.40 units/ml 였고, 50mM EDTA에 의하여 활성이 억제되었으며, 기본배지에 soluble starch와 Ca2+, Mg2+, Mn2+을 첨가했을 때 활성이 비교적 높았고, pH6.5와 7.0 사이에서, 온도 55℃에서 비교적 활성이 높았다. 아밀라제 생산을 위한 최적 배지로는 0.2% soluble starch, 1.0% bacto-peptone, 0.3% beef extract, 0.5% NaCl, 0.3% K2-KH2PO4, 0.012% CaCl.2H2O, 0.005% MnSO4.H2O, 0.03% MgSO4.7H2O이었다. 효소 용액을 에 HPO4, 0.1% 탄올 침전시켜 5ml의 0.1M 인산염 완충액에 용해한 용액의 비활성은 2.01 units/mg였고, starch에 대한 효소의 Km 값은 0.80 mg/ml였다.
The extracellular amylase production by Bacillus thuringiensis subsp. kurstaki HD-l in amylase production media and its characteristics were investigated. The amylase production was highest in the medium composed of 0.2% soluble starch, 1.0% Bacto-peptone, 0.3% beef extract, 0.3% yeast extract, 0.5% NaCl, 0.3% K2HPO4, 0.1% KH2PO4, 0.012% CaCl2.2H2O, 0.005% MnSO4.H2O, and 0.03% MgSO4.7H2O. The amylase activity was inhibited by 50mM EDT A. The enzyme was optimally active from pH 6.5 to 7.0 at 55℃, The specific activity of the enzyme in the ethanol precipitate was 2.01 units/mg, and the Km value was approxi-mately 0.8 mg/ml.
