重组枯草芽孢杆菌产极端耐热木聚糖酶条件的优化

Optimization of extreme-thermostable xylanase B production by Bacillus subtilis-xyB in liquid state fermetation

对基因工程菌Bacillus subtilis-xyB在摇瓶发酵水平产极端耐热木聚糖酶条件进行了优化。结果表明:该基因工程菌发酵产极端耐热木聚糖酶的优化后的培养基配方是:4%麸皮、1%(NH4)2HPO4、0.1%K2HPO4、0.2%吐温80、1mmol/LFe2+,初始pH为自然值(7.0)。优化后的摇瓶发酵条件是:36℃、转速180r/min、500mL三角瓶中加入50mL培养基、接种量2%。采用优化后的培养基发酵培养18h酶活力达到最大值10.71XU/mL。与优化前相比,产酶最高峰提前6h,而木聚糖酶活力是优化前的2.5倍,本实验得到的优化发酵条件大大提高了重组菌产酶能力。

Bacillus subtilis-xyB was a novel gene-engineering strain which was constructed in our lab. The optimal fermentation conditions of extreme-thermostable xylanase by Bacillus subtilis-xyB was investigated in this paper. The results showed that the optimal condition for enzyme production were 4% wheatbran, 1% （NH4）2HPO4, 0.1% K2HPO,, 0.2% Tween 80 and some trace elements（Fe^2＋ lmmol/L） with 18 h cultivation at pH 7.0, 36 ℃, 500 mL shark flasks with 50 mL media, 2% inoculation and 180 r/min. Under such a condition, the enzyme activity can reach 10.71 XU/mL, which was 2.5 times higher than pre-optimization and the fermentation time was shortened 6 h.