【摘要】 从淀粉加工厂附近的土壤中分离出一株产耐热、嗜碱性支链淀粉酶的菌株 ,初步鉴定为嗜碱芽孢杆菌 SX- 12 .优化后的最佳发酵培养基为 :可溶性淀粉 3.0 g,蛋白胨 1.0 g,酵母膏 0 .5 g,K2 HPO4 0 .2 g,Mg SO4 · 7H2 O 0 .0 5 g,最适 p H 8.5 ,最适温度 4 0℃ .酶活从最初的 2 .4 u/ m L提高到 4 .6 2 u/ m L .酶的最适 p H 9.0 ,最适温度 5 5℃ .Ca2 + ,Mn2 + ,Mg2 + 等离子是酶的激活剂 ,Zn2 + ,Hg2 + 等离子是抑制剂 .更多还原

【Abstract】 A bacteria-producing amylopectase was isolated from soil and identified to be Bacillus sp. The fermentation medium and culture conditions of the strain were investigated. The optimal mediums for fermentation are soluble starch 3.0 g, pepton 1.0 g,yeast extract 0.5 g, K 2HPO 4 0.2 g, MgSO 4·7H 2O 0.05 g.The optimum temperature is 40℃. The optimum pH is 8.5. The enzyme activity was increased from 2.4 to 4.62 u/ mL. The optimum temperature for enzyme is 55 ℃. The optimum pH is 9.0. The enzyme activity was promoted by Ca 2+,Mn 2+,Mg 2+, but inhibited by Zn 2+,Hg 2+.更多还原