产β-mannanase内生菌的诱变育种和酶学特性研究  

Mutation Breeding of a β-Mannanase-producing Endophytic Bacteria and its Enzymatic Characterization

作　　者：张建新[1] 张吨[2] 王海磊[1] 胡文波[1] 韩科芳[1] 朱岩昆[1] 赵杰[1] 聂国兴[1] 

机构地区：[1]河南师范大学生命科学学院,河南新乡453007 [2]周口科技职业学院,河南周口466000

出　　处：《现代食品科技》2012年第10期1331-1335,1410,共6页Modern Food Science and Technology

基　　金：河南省重点科技攻关(112102110118);河南省教育厅科技攻关(2010A180014)

摘　　要：以实验室筛选的产伊甘露聚糖酶的黄豆内生菌Bacillussubtilis HD-1（54．6U／mL）为出发菌株，分别采用紫外线，硫酸二乙酯，紫外线-光复活和紫外线．硫酸二乙酯对其进行诱变，结果表明，以紫外线-硫酸二乙酯复合诱变效果最好，获得-株高产伊甘露聚糖酶的突变菌株BacillussubtilisLID．20，酶活达89．5u／mL，比出发菌株提高了63．9D／01遗传性能稳定。该伊甘露聚糖酶的最适反应温度和pH分别为50℃和7．0，该酶在50℃以下，pH5．0-8．0之间稳定性较好，属于中性酶。亚铁离子和钴离子对酶有较强的激活作用，相对酶活分别提高了13．2％和31．7％，但锰离子对酶有强烈的抑制作用，相对酶活仅有对照组的55．6％；金属离子钾、钙、钴和钡都能增强酶热稳定性，其中钴离子的增强效果最为明显，残余酶活约是对照组的1．5倍。The mutagenic effects of the ultraviolet ray, diethyl sulfate＇s single factor and ultraviolet-diethyl sulfate compound mutagenesis on Bacillus subtilis HD-1 （54.6 U/mL） were studied. Results of enzyme activity showed that ultraviolet-diethyl sulfate compound mutagenesis was better. A mutant strain, named Bacillus subtilis UD-20 with high-level β-mannanase production was obtained after ultraviolet-diethyl sulfate compound mutagenesis from Bacillus subtilis HD-1 which was an endophytic bacteria screened from soybean seeds. The fl-mannanase activity of Bacillus subtilis UD-20 increased 63.9% compared with that of the original sWain Bacillus subtilis HD-1 （54.6 U/ml） and was stable during the generations. The optimal temperature for β-mannanase activity was 50 ℃ and the enzyme was stable up to 50℃. The optimal pH for enzyme activity was 7.0 and the enzyme demonstrated broad pH stability within a pH range of 5.0-8.0. The β-mannanase activity was activated by Fe2＋ （113.2%） and Co2＋（131.7%）, but strongly inhibited by Mn2＋ （55.6%）. The fl-mannanase stability was increased by K＋, Ca2＋, Ba2＋, among which Co2＋ （150%） showed the best effect on the enzyme stability.

关 键 词：内生菌 Β-甘露聚糖酶 诱变 酶学斗寺I陛 热稳定性 

分 类 号：TQ925[轻工技术与工程—发酵工程]