一株产过氧化氢酶细菌的筛选及发酵条件的优化

Screening of catalase-producing strain and optimization of culture conditions

文中筛选到一株过氧化氢酶生产菌株,初步鉴定为枯草芽孢杆菌(Bacillus sp.).对葡萄糖浓度、NaNO3浓度、培养温度、培养时间、摇床转速和培养基初始pH等对该菌株发酵特性的影响进行了单因素实验,并在此基础上采用响应曲面法(RSA)对其发酵条件进行了进一步优化.结果表明:NaNO3浓度和摇床转速的一次项和二次项、培养时间的二次项、NaNO3浓度和摇床转速的交互项以及NaNO3浓度和培养时间交互项对过氧化氢酶酶活均有显著影响;NaNO3浓度为4.0 g/L、培养时间为30 h和摇床转速为199 r/min时,酶活达到最大值211.84 U/mL.

Catalase is widely applied in the food,textile and chemical industries.A strain,which was a catalase over-producer,was isolated and identified as Bacillus sp.Single-factor experiments including glucose concentration,NaNO3 concentration,culture temperature,culture time,rotary speed,the initial pH of medium were carried out to optimize the conditions for catalase production.Based on this,response surface analysis method was used for further enhancing catalase production.The results showed that the linear and quadratic term of NaNO3 concentration and rotary speed,the quadratic term of culture time,and the interactive effects of NaNO3 concentration with both rotary speed and culture time were significant.The optimal culture conditions were as follows.The NaNO3 concentration was 4.0 g/L,the cultural time was 30 h,and the rotary speed was 199 r/min.Under these conditions,the maximum enzyme activity reached 211.84 U/mL.