中温α-淀粉酶的酶学性质研究

食品科学 ›› 2008, Vol. 29 ›› Issue (9): 373-377.

中温α-淀粉酶的酶学性质研究

刘洋, 沈微, 石贵阳, 王正祥

江南大学工业生物技术教育部重点实验室；

出版日期:2008-09-15 发布日期:2011-12-08

Enzymatic Properties of Mesophilic α-Amylase from Bacillus amyloliquefaciens M23

LIU Yang, SHEN Wei, SHI Gui-Yang, WANG Zheng-Xiang

Key Laboratory of Industrial Biotechnology,Ministry of Education,Jiangnan University,Wuxi 214122,China

Online:2008-09-15 Published:2011-12-08

摘要/Abstract

摘要： 通过盐析、DEAE-FF和Superdex-75,对Bacillus amyloliquefaciens M23产生的α-淀粉酶进行了纯化,得到电泳纯的α-淀粉酶,纯化倍数为29.61,活力回收率为20.06%。用SDS-PAGE测得该酶的分子量为58kD。该酶的最适反应温度为55℃,最适反应pH值为6.0。纯酶液在pH7.0～10.0缓冲液中室温放置24h,可保持80%以上活力。55℃保温15min,基本丧失活力,添加10mmol/L的Ca²⁺能显著提高酶的热稳定性。Ca²⁺、Mg²⁺和Co²⁺具有激活该酶活性的作用,EDTA抑制酶的活性。60℃,以可溶性淀粉为底物的Km,Vmax,分别为4.33g/L、1.19g/L·min。薄层层析结果表明该酶水解淀粉生成糊精和寡聚糖。

关键词: Bacillus amyloliquefaciens； &alpha, -淀粉酶；纯化；性质；

Abstract: α-Amylase from B. amyloliquefacens M23 was purified to electrophoretic homogeneity. The molecular weight of the purified α-amylase is 58 kD. Its optimum pH value of is in the range from 5.5 to 6.5,and the optimum temperature is 60 ℃. With in 24 h at room temperature 80% enzyme activity keeps in the pH range from 7.0 to 10.0. The most enzyme activity loses within 15 min at 55 ℃. But, the enzyme would be stable for 1 h with the presence of 10 mmol/L Ca2+. EDTA inhibits the enzyme activity, while, Ca²⁺、Mg²⁺和Co²⁺ ions are activators. Km and Vmax of α-amylase to soluble starch is 4.33 g/L and 1.19 g/L· min, respectively. The main hydrolysates to soluble starch are oligosaccharides and dextrin.

Key words: Bacillus amyloliquefaciens； &alpha, -amylase； purification； characterization property；

刘洋, 沈微, 石贵阳, 王正祥. 中温α-淀粉酶的酶学性质研究[J]. 食品科学, 2008, 29(9): 373-377.

LIU Yang, SHEN Wei, SHI Gui-Yang, WANG Zheng-Xiang. Enzymatic Properties of Mesophilic α-Amylase from Bacillus amyloliquefaciens M23[J]. FOOD SCIENCE, 2008, 29(9): 373-377.