影响产气肠杆菌EAM-Z1中嘧啶核苷磷酸化酶活力的因素

Factors affecting the enzyme activity of PyNPase in EAM-Z1

目的:研究影响产气肠杆菌EAM-Z1的嘧啶核苷磷酸化酶(PyNPase)酶活力的因素。方法:分别考察添加底物、金属离子、速效碳源和磷酸盐对菌体浓度及PyNPase活力的影响。结果:加入4 g/L胞苷,菌体的量增加了19.30%,综合考虑对菌体量和比酶活,加入3 g/L胞苷可使PyNPase活力增加10.46%;4 mg/L Ca2+使菌体量增加了10.90%,PyNPase活力增加了30.25%;低浓度的速效碳源可以增加菌体浓度,但均使PyNPase的活力降低;1 g/L磷酸盐使PyNPase活力增加了17.40%。结论:底物诱导、金属离子、速效碳源和磷酸盐均对PyNPase的活力有一定的影响。

Aim：To study the factors affecting the enzymatic activity of pyrimidine nucleoside phosphorylase （PyNPase）. Mothods：The influences of the substrate inducer, metalic ion, quick-carbon source and phosphate on the cell concentration and enzyme activity of PyNPase were investigated. Results： Cytidine （1 g/L） enhanced the cell concentration by 19.30%, and cytidine （3 g/L） enhanced the enzymatic activity by 10.46%. Ca^2＋ （4 mg/L） can increase the cell concentration by 10.90% and increase the enzyme activity by 30.25%. Quick-carbon source of low concentration enhance the cell concentration but attenuated the enzymatic activity. Phosphate （1 g/L） increased the enzyme activity by 17.40%. Conclusion： Substrate inducer, metallic ion and phosphate are available measures to enhance the activity of PyNPase.