产γ-聚谷氨酸枯草芽胞杆菌菌株的高效诱变及发酵条件优化

Mutagenesis of Poly-γ-Glumatic Acid High-Producing Bacillus subtilis Strain and Optimization of Fermentation Condition

以产γ-聚谷氨酸(γ-PGA)枯草芽胞杆菌菌株SY-ND为出发菌株,采用新型常压室温等离子体技术对其进行诱变以期获得高产菌株,在诱变致死率为80%~98%的条件下,通过检测突变菌株发酵产γ-PGA的量,筛选得到一株高产菌株SY-ND-SFX029。通过正交试验优化得出最佳培养基条件为:蛋白胨8.0g·L-1、蔗糖45.0g·L-1、L-谷氨酸钠35.0g·L-1。依照该条件经过48h发酵,菌株SY-ND-SFX029的γ-PGA产量达35.3g·L-1,比出发菌株SY-ND的γ-PGA产量18.9g·L-1提高86.8%。

Poly-γ-glumatic acid(γ-PGA)-producing Bacillus subtilis strain SY-ND was mutagenized to 80% ~98% mortality rate by atmospheric pressure and room temperature plasma(ARTP).Aγ-PGA high-producing strain SY-ND-SFX029 was screened out by evaluating the yield ofγ-PGA in the mutagenized strains.Liquid fermentation conditions of strain SY-ND-SFX029 were optimized by orthogonal experiment,and the optimized conditions were 8.0g·L-1 peptone,45.0g·L-1 sucrose and 35.0g·L-1 L-glutamate.Under this optimized fermentation condition for48 h,γ-PGA yield of strain SY-ND-SFX029 was 35.3g·L-1,which increased 86.8%compared to the 18.9g·L-1yield ofγ-PGA by the original strain SY-ND.