亚硝酸盐还原酶高产菌株的筛选与产酶条件的研究

Screening of High-yielding Nitrite Reductase Strains and Study on Conditions of Enzyme Production

该文从泡菜中筛选到一株高产亚硝酸盐还原酶的菌种N-6,经16SrDNA序列测序鉴定为鼠李糖乳杆菌(Lactobacillus rhamnosus)。通过优化培养基中不同碳源、氮源、磷源等营养成分、培养方式、培养温度等条件,鼠李糖乳杆菌N-6的最适培养基为:2%葡萄糖、0.5%酪蛋白胨、0.2%磷酸氢二钾,37℃通气培养,通过硫酸铵分级盐析、透析、二乙基氨基乙基纤维素(diethylaminoethylcellulose,DEAE)柱层析等方法对亚硝酸还原酶进行纯化,酶活力由60.83 U/mL提高到764.49 U/mL,有效地提高了酶纯度。

The strain N-6,which produces high levels of nitrite reductase,was screened from pickles.It was i-dentified as Lactobacillus rhamnosus by 16SrDNA sequencing.Nutrient composition(using different carbon,nitrogen,and phosphorus sources),cultivation method,cultivation temperature,and other conditions were op-timized.The optimal medium for L.rhamnosus N-6 was as follows:2%glucose,0.5%casein peptone,0.2%dipotassium hydrogen phosphate,aerobic culture at 37℃.Purification of nitrite reductase by ammonium sulfate gradient precipitations,dialysis,diethylaminoethylcellulose anion exchange chromatography,yielded an in-crease in enzyme activity from 60.83 U/mL to 764.49 U/mL,effectively improving the purity of nitrite reductase.