短小芽孢杆菌碱性蛋白酶的提纯与性质研究  

Purification and partial properties of alkaline protease Zkud202-4 from Bacillus pumilus

作　　者：褚忠志[1] 于新[2] 

机构地区：[1]甘肃农业大学食品科学与工程学院,甘肃兰州730070 [2]广东仲恺农业技术学院,广东广州51000

出　　处：《甘肃农业大学学报》2008年第6期166-169,173,共5页Journal of Gansu Agricultural University

基　　金：国家自然科学基金项目(30471217);广东省自然科学基金项目(33311);广东省科技计划项目(2005B20401002)

摘　　要：将短小芽孢杆菌(Bacillus pumilus)Zkud202-4液体的发酵液离心去菌体,用硫酸铵盐析得粗酶,透析除盐后进行Sephadex G-75柱层析得到电泳纯碱性蛋白酶,用该法提纯的碱性蛋白酶比活力从粗酶液的155.5 U/mg提高到了954 U/mg,回收率为27.6%.该酶水解酪蛋白的最适反应温度为50℃,最适作用pH为10,且该酶具有较高的热稳定性和耐碱性.经SDS-PAGE测定,其分子质量约为2.5 ku.The fermented liquit medium by Bacillus pumilus strain Zkud202-4 was centrifuged,and the supernatants were purified through the process involving ammonium sulfate precipitation, Sephadex G-75 filtration. The specific activity of enzyme was increased from 155.5 U/mg to 954 U/mg with the recovery of 27.6 %. The optimal temperature and pH for casein hydrolysis were 50 ℃ and 10 respectively. The purifled proteinase was demonstrated to be heat stable and suitable in alkaline. The alkaline protease of electrophoretic homogeneity by SDS-PAGE showed the product was a protein with a molecular weight of 2.5 ku.

关 键 词：短小芽孢杆菌 碱性蛋白酶 提取纯化 性质 

分 类 号：Q939.9[生物学—微生物学]