环状芽孢杆菌产β-甘露聚糖酶的产酶条件及粗酶性质研究

Studies on the Condition and Some Properties of β-mannanase Produced by Bacillus circulans WXY-100

为确定环状芽孢杆菌WXY-100的最佳摇瓶培养工艺，采用了L9（3^4）正交试验对培养基成分以及培养条件进行了优化。结果表明，最佳培养基成分为：酵母抽提物20g／L，魔芋粉20g／L，（NH4）2SO4 2g／L，KH2PO4 1g／L，MgSO4·7H2O 1g／L。最佳培养条件为：种龄8～12h，接种量为6％，装液量为25mL，pH7．5，培养温度40℃，培养时间25h。该酶在pH4～8和60℃以下稳定，作用最适条件是pH5．0和60℃，Cu2^＋和Co^2＋对酶有较显著的激活作用，而Hg^2＋对酶有强烈的抑制作用。

To study the optimal technical conditions of shaking fermentation for producing β-mannanase by Bacillus circulans WXY-100, the culture ingredients and conditions were optimized with the orthonormal table L9 （3^4） method. Studies showed that the culture components for optimization of the enzyme production were yeast extract 20 g/L, Konjak powder 20 g/L, （NH4）2SO4 2 g/L, KH2PO4 1 g/L and MgSO4·7H2O 1 g/L; and the optimal culture conditions were seed incubation time 8 - 12 h, inoculation ratio 6 %, medium volume 25 mL, pH 7.5, fermentation temperature 40 ℃ and fermentation time 25 h. The enzyme was stable between pH 4 - 8 and below 60 ℃. The optimal pH and temperature for enzyme activity were 5.0 and 60 ℃ respectively. Cu^2＋ and Co^2＋ had a remarkable influence on increasing the activity of β-mannanase, while Hg^2＋ was on the contrary.