摘要
以海藻酸钠为载体,对鞘氨醇单胞菌SC-1产3-苯氧基苯甲酸（3-PBA）降解酶进行固定化,探讨酶的固定化条件及固定化酶的酶学性质。结果表明,当酶液与海藻酸钠体积比为1∶5、海藻酸钠质量分数2%、氯化钙质量分数1%时,固定化酶的酶活较高,固定化时间对酶活影响不显著,而固定化酶凝珠直径对其酶活影响较大,在最优条件下固定化酶的酶活达223.1 U/g,酶活回收率为86%。在30℃,p H 7.0时固定化酶的酶活达到最高值;Mg2＋,Mn2＋及较高浓度Ba2＋,低浓度Cu2＋,10-2~10-6mol/L EDTA,0.01%BSA,10-6mol/L邻菲罗啉,0.1%VC对固定化酶的酶活有促进作用。固定化酶的米氏常数（Km）为46.63×106nmol/L,最大反应速率（Vmax）为3.70×103U/g。固定化3-PBA降解酶在最适条件下连续反应900 min,对5μg/m L的3-PBA降解率为26.14%。
Sodium alginate was used for immobilization of 3-phenoxyzoic acid（3-PBA）-degradation enzyme which was produced by Sphingomonas sp. SC-1. The effects of immobilized enzyme and the immobilized enzyme properties were studied. The results showed that the optimal immobilized condition of 3-PBA-degradation enzyme was： a ratio of enzyme liquid and sodium alginate 1 ∶5（V/V）, sodium alginate and calcium chloride concentration at 2% and 1% respectively.Immobilization time had no obvious effect on enzyme activity, but immobilized enzyme particle diameter had great influence on it. Under the optimum conditions. The activity of immobilized enzyme reached 223.1 U/g and the activity recovery reached 86%. The highest enzyme activity appeared while reaction temperature was 30 ℃, and p H was 7.0; Mg2＋, Mn2＋and high concentrations of Ba2＋, low concentration of Cu2＋can promote the immobilized enzyme activity; 10-2-10-6mol/L ethylene diaminetetraacetic acid, 0.01% bovine serum albumin, 0.1% vitamin C, 10-6mol/L phenanthroline had promoting effect on enzyme activity. The michaelis constant（Km） of immobilized enzyme was 46.63 ×106nmol/L, maximum reaction rate（Vmax） was 3.70×103U/g. The degradation rate of 3-PBA immobilized enzyme to 5 μg/m L 3-PBA was 26.14% after900 minutes continuous reaction under the optimum conditions.
出处
《中国食品学报》
EI
CAS
CSCD
北大核心
2016年第2期9-17,共9页
Journal of Chinese Institute Of Food Science and Technology
基金
国家自然科学基金面上项目(31371775)
