一株产α-淀粉酶菌株的分离筛选、鉴定及酶学性质研究  

Screening and identification of an α-amylase-producing strain and its enzymatic property

作　　者：赵淑琴 杨孝朴[2] 

机构地区：[1]甘肃农业大学基础实验教学中心,甘肃兰州730070 [2]甘肃农业大学动物医学院,甘肃兰州730070

出　　处：《中国酿造》2018年第2期60-65,共6页China Brewing

基　　金：甘肃农业大学校基金(GSAU-STS-1637)

摘　　要：为了更加经济、更高产量的分离出高纯酶,该实验从富含淀粉的土壤中筛选出1株高产淀粉酶的菌株LZ-10,通过菌落形态观察、生理生化特性实验、16S r DNA序列和gyr B基因序列分析对其进行鉴定。采用硫酸铵盐析,DEAE-52阴离子交换纤维素纯化,用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)检测蛋白分子质量。结果表明,菌株LZ-10鉴定为枯草芽孢杆菌(Bacillus subtilis)。纯化后的淀粉酶比活力为59.91 U/mg,纯化倍数为4.53,回收率为60.5%,分子质量为55.4 k Da。对其酶学性质进行研究,得出菌株LZ-10所产淀粉酶最大酶活力为41.6 U/m L,最适作用温度为50℃,在50~70℃温度环境下其稳定性较高;最适p H值为7.0,在p H=5.0~7.0的环境条件下稳定性较高;Ca^(2+)、Mg^(2+)、Na^+、K^+对淀粉酶有激活作用;乙二胺四乙酸(EDTA)、Fe2+、Zn2+对淀粉酶有抑制作用。In order to isolate high-purify enzyme with high production economically, a high yield amylase-producing strain was isolated i^om soil sam-ples, named as strain LZ-10. The strain was identified by colony morphology observation, physiology and biochemistry experiments, 16S rDNA and gyrB gene sequence analysis. Adopting the method of ammonium sulfate precipitation, DEAE-52 anion exchange purification, finally the molecular mass was detected using sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）. The results showed that the strain LZ-10 was iden-tified as Bacillus subt^ilis. The specific activity of purified amylase was 59.91 U/mg, the purified multiple was 4.53, the recovery rate was 60.5% and the molecular mass was 55.4 kDa. The study about enzymatic properties showed that the maximum enzyme activity of amylase from strain LZ-10 was 41.6 U/ml, the optimal operative temperature was 50 V., and the stability of amylase was higher at the temperature range of 50-70 V., and the optimal pH was 7.0, the stability of amylase was higher at the pH range of 5.0-7.0. Ca2＋, Mg2＋, Na＋, K＋ showed active effect on amylase, and ethylene diamine tetraacetic acid （EDTA）, Fe2＋, Zn2＋ showed inhibiting effect on amylase.

关 键 词：Α-淀粉酶 分离筛选 鉴定 纯化 酶学性质 

分 类 号：Q93-331[生物学—微生物学]