产β-甘露聚糖酶内生菌最适发酵条件的优化

Optimization of producing β-mannanase endophyte optimum fermentation conditions

植物内生菌是一类种类丰富、生物学功能多样的微生物。试验研究将黄豆中筛选出的1株酶活力较高的枯草芽孢杆菌内生菌HD-1,在摇瓶发酵培养水平,对发酵pH值、温度、转速、接种量、发酵时间及培养基成分进行优化。结果表明,发酵最适培养条件为:温度35℃、pH值7.0、转速200 r/min、发酵72 h、接种量5%;发酵最适产酶培养基组成:魔芋粉3%、(NH4)2SO40.375%;最优的离子浓度分别为FeSO40.001%、NaCl 0.5%、MgSO40.01%,此时HD-1的产酶水平达到98.3 U/ml,约是初始酶活力的1.8倍,发酵罐验证试验得到酶活高达193.12 U/ml。

Endophyte is a genus of microbe which can be divided into several categories and it has various kinds of biological functions. In this study, a higher enzyme activity of Bacillus subtilis endophyte HD-1 that was screened out from soybeans. In the fermentation level of training, the fermentation pH, temperature, rotation speed, inoculum size, fermentation time were utilized to optimize the medium com- position.The results showed that the optimal fermentation of culture conditions was temperature 35 ~C, pH 7.0, rotation speed 200 r/rain, fermentation time 72 h, inoculum size 5%. The optimal fermentation of medium composition for enzyme production is konjac flour 3%, （NH4）2SO4 0.375%, the optimal concentration of FeSO4, NaCl and MgSO4 are 0.001%, 0.5%, 0.01%. Under the conditions mentioned above, enzyme activity reached 98.3 U/ml, with 1.8 times of the initial enzym activity. And the fermentation activity of experimental verification was up to 193.12 U/ml.