羟基乙腈水解酶菌株的筛选及其催化特性

摘要

A strain CCZU-12 with high glycolonitrile-hydrolyzing activity has been isolated using gly-colonitrile as sole nitrogen source. It was identified as Pseudomonas sp. By its morphological, physiological properties and 16S rDNA sequence analysis. The preferred carbonitrogen sources and metal ions were sodium acetate (10 g/L), yeast extract (5 g/L), and Mg2+ (1.0 mmol/L), respectively. The optimum culture conditions were the filling volume 50 mL in 250 mL shaking flask, inoculum 4%, temperature 30 ℃, and initial pH 7.0. After hydrolysis of glycolonitrile for 120 h, glycolic acid was obtained in a yield of 98.9% at the optimum reaction temperature 35 ℃ and pH 7.0.%以羟基乙腈为唯一氮源，从土壤中筛选到一株腈水解酶产生菌CCZU-12，经形态观察、生理生化实验和16S rDNA序列分析，鉴定该菌为假单胞菌属(Pseudomonas sp.)。对菌株CCZU-12产腈水解酶的培养条件及催化反应条件进行优化，最适产酶培养条件为：碳源为10 g/L乙酸钠，氮源为5 g/L酵母粉，金属离子为1.0 mmol/L Mg2+，培养温度30℃，pH值7.0，接种量4％，装液量50 mL/250 mL；最适催化反应温度35C，pH值7.0，反应120 h，羟基乙腈转化率达到98.9％。