产蛋白酶芽孢杆菌的筛选、耐酸性驯化及蛋白酶酶学性质分析  

Screening and acid resistance acclimatization of protease-producing Bacillus and enzymatic characteristics analysis

作　　者：张璋 赵腾飞 李红霞 宋露露 ZHANG Zhang;ZHAO Tengfei;LI Hongxia;SONG Lulu(Department of Brewing Engineering,Moutai Institute,Zunyi 564507,China)

机构地区：[1]茅台学院酿酒工程系,贵州遵义564507

出　　处：《中国酿造》2024年第1期84-90,共7页China Brewing

基　　金：遵义市科技计划项目(遵市科合HZ字[2021]314号);遵义市科技计划项目(遵市科合HZ字[2020]318号);茅台学院高层次人才科研启动经费项目(mygccrc[2022]003);国家自然科学基金地区科学基金项目(32260229)。

摘　　要：该研究利用透明圈法及蛋白酶活力测定从高温大曲中筛选高产蛋白酶的菌株,通过形态学观察和分子生物学技术对其进行菌种鉴定。进一步对筛选菌株的耐酸性进行驯化,并对其耐受性及所产蛋白酶酶学性质进行研究。结果表明,分离筛选到一株高产蛋白酶活力的菌株Cy3,经鉴定为蜡样芽孢杆菌(Bacillus cereus),其在最适生长pH 6条件下所产蛋白酶活性为505.0 U/m L。通过对菌株Cy3进行耐酸性驯化后,得到菌株Cy3-驯,成功将其生长p H驯化至5,培养15 h时OD600 nm值提高2.54倍。菌株Cy3-驯所产蛋白酶的最适反应温度从60℃提高至70℃,最适反应p H值为6,但活性及稳定性略有下降。菌株Cy3-驯具有较好的NaCl和葡萄糖耐受性,最高耐受含量分别为15%和60%,同时在乙醇体积分数8%以及乳酸体积分数3%时仍能生长。A high protease-producing strain was screened from high-temperature Daqu by transparent circle method and protease activity determination,and identified by morphological observation and molecular biological technique.The acid tolerance of the screened strain was further acclimated,the tolerance was analyzed,and theenzymatic characteristics of protease produced by the screened strain were studied.The results showed that thestrain Cy3 with high protease activity was isolated and screened,and identified as Bacillus cereus,and the protease activity was 505.0 U/ml under the optimal growth condition of pH 6.The strain Cy3-acclimation was obtained after acid tolerance acclimatization for strain Cy3,and its growth pH was successfully acclimated to 5,and the OD600 nm value increased by 2.54 times after culture for 15 h.The optimum reaction temperature of protease produced by strain Cy-3-acclimation was promoted from 60℃to 70℃,and the optimum reaction pH was 6.However,the protease activity and stability were slightly decreased.The strain Cy3-acclimation had high tolerance to NaCl and glucose,with the maximum tolerance mass fraction of 15%and 60%,respectively,and could still grow when the volume fraction of ethanol and lactic acid was 8%and 3%,respectively.

关 键 词：蛋白酶 芽孢杆菌 分离鉴定 耐酸性驯化 酶学性质 

分 类 号：TS261.1[轻工技术与工程—发酵工程]