摘要
以从烟叶表面筛选得到的巨大芽孢杆菌Bck（Bacillus megatherium）为出发菌株，经理化诱变处理，采用透明圈法进行初筛，即在淀粉培养基和蛋白培养基平板上挑取Hc值（透明圈直径与菌株直径之比）较大的菌株，然后对这些菌株进行摇瓶复筛，测定发酵液α-淀粉酶和蛋白酶的活性，得到酶活性较高的菌株B80其产生的α-淀粉酶活性是Bck的1.964倍，蛋白酶活性是Bck的2．266倍。该菌株能稳定遗传，经五代传代培养后，其产生的α-淀粉酶和蛋白酶活性分别稳定在2．821-3．273U／mL和21．21-27．36U／mL范围内。
The spores of Bacillus megatherium （BcK） from tobacco leaf surface were mutagenized physically and chemically. From the plates with soluble starch and casein mediums, the strains with higher Hc value （the diameter ratio of clearing ring and colony） were selected. The selected strains were repeatedly screened by shaking along with measuring α-amylase and protease activities in fermentative liquid, strain Bs of higher activity was obtained, whose α-amylase and protease activities were 1.964 and 2.266 times of that of BCK, respectively. The strain has a good genetic stability after 5 -generation subculture, its α-amylase and protease activities stabilized within the ranges of 2.821-3.273 U/mL and 21.21-27.36 U/mL, respectively.
出处
《烟草科技》
EI
CAS
北大核心
2008年第8期53-57,共5页
Tobacco Science & Technology
基金
国家烟草专卖局资助项目"烟草微生物发酵增香机理与增香技术研究"(合同号110200401014)
关键词
烟叶
巨大芽孢杆菌
Α-淀粉酶
蛋白酶
诱变
Tobacco leaf
Bacillus megatherium
α- Amylase
Protease
Mutagenesis
