| 摘要: |
| 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·min-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·min-1;pH9.0时Km29.9945mmol·L-1,Vm 0.2165 mmol·L-1·min-1. |
| 关键词: 基因工程菌 木聚糖酶 培养优化 酶学性质 |
| DOI： |
| 分类号:Q93 |
| 基金项目: |
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| Cultural Optimization of Engineered Strain 1020 and Some Enzymatic Properties of Xylanase |
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| Abstract: |
| 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. |
| Key words: genetic engineered strain xylanase cultural optimization enzymatic properties |
