一株产α-淀粉酶细菌的分离、鉴定及酶学性质初步研究

Screening,Identification and Characterization of an α-amylase-Producing Bacillus subtilis 2N02

利用纯培养和碘液显色从松毛虫幼虫肠道中分离筛选得到一株产α-淀粉酶细菌2N02,通过16S rDNA序列比对,鉴定为枯草芽孢杆菌。摇瓶发酵后,产生的α-淀粉酶酶活力20.0 U/mL;经硫酸铵沉淀、透析脱盐后,初步研究酶学性质,测得酶反应最适温度50℃,最适pH值6.5,Mg2+、Ca2+对酶具有激活作用,Zn2+和EDTA则抑制酶活性。研究表明,该菌株是产α-淀粉酶较好的材料,具有一定的应用前景。

An α-amylase-producing strain was isolated from Dendrolimu intestine by plating method and screening with iodine solution.The strain 2N02 was identified as Bacillus subtilis based on 16S ribosomal DNA sequence alignment analysis in the GenBank database.After shaking flask culture,the yield of α-amylase reached 20.0 U/mL.The enzyme properties of the strain were examined after ammonium sulfate precipitation and dialysis for desalting.The results showed that the optimum temperature and pH of the enzyme were 50 C and 6.5 respectively,the enzyme activity was stimulated by Mg2＋ and Ca2＋,while obviously inhibited by Zn2＋ and EDTA.This study provided a good experimental material for the further industrial utilization about α-amylase production.