基因工程菌1020的培养优化及木聚糖酶部分特性研究

对基因工程菌1020培养基成分及培养条件进行了优化。结果表明,Mg2+、Mn2+、Zn2+三种金属离子可促进发酵产木聚糖酶。180 r.m in-1的摇床转速可满足70 mL/500 mL装液量的溶氧需求。最适培养温度为30℃,pH值为7.0。优化后的酶活为优化前的2.09倍。全细胞木聚糖酶的酶学性质表明该酶有两个最适pH值,分别为7.0与9.0。金属离子Ca2+,Fe3+,Fe2+对酶活有促进作用。pH7.0时Km为36.7095 mmol.L-1,Vm为0.3829 mmol.L-1.m in-1;pH9.0时Km29.9945mmol.L-1,Vm 0.2165 mmol.L-1.m in-1。

Cultural Optimization of Engineered Strain 1020 and Some Enzymatic Properties of Xylanase

First,the fermentation medium and cultural condition of genetic engineering strain 1020 had been optimized.The results showed that Mg~(2+) 、Mn~(2+) and Zn~(2+) could stimulate enzymatic activity.The agitation speed of 180r·min~(-1) could satisfy the dissolved oxygen demand of 70mL medium in 500mL flask.The suitable culture conditions were 30℃ and pH7.0. Xylanase activity was 2.41 times as in the original medium.And the enzymatic property experiments showed that xylanase in whole cell displayed an optimum pH of 7.0 and 9.0,Ca~(2+),Fe~(3+) and Fe~(2+) could accelerate enzymatic activity.At pH7.0,the kinetic parameters Km and Vm were 36.7095mmol·L~(-1) and 0.3829mmolL~(-1)·min~(-1).And at pH9.0,they were 29.9945mmol·L~(-1)(Km)and 0.4005 mmolL~(-1)·min~(-1) respectively.