以假单胞茵(Pseudomonas sp.)为出发菌株,通过紫外诱变筛选得到一株γ-谷氨基甲酰胺合成酶高产菌株UV-19,其酶活提高32.54%.以突变株UV-19为供试菌株,对γ-谷氨基甲酰胺合成酶的发酵条件进行优化.首先利用Plackett-Burman设计筛选出影响较大的4个因素:葡萄糖、蛋白胨、起始pH值、装液量.在此基础上再利用CCD响应面分析法进行优化,得到最佳产酶培养条件为(g/L):葡萄糖15、蛋白胨12、NaCl 5.0、MgSO4·7H2O 0.2、K2HPO4·3H2O 0.5、甲胺盐酸盐1.0g/L、起始pH值6.5、装液量72mL/250mL.该优化条件下进行产酶培养,假单胞菌发酵产γ-谷氨基甲酰胺合成酶酶活力可达32.68U/mL.%Pseudomonas sp. was used as initial strain to isolate the high activity strain by means of mutation under the UV-light treatment. One strain UV-19 with higher enzymatic activity of γ-glutamylmethylamide synthetase increased by 32. 54％ was obtained. The culture medium components and enzyme production conditions of mutant strain UV-19 were optimized by response surface methodology.Initially , Plackett-Burman design was used to evaluate the process variables which were relevant to the enzyme production. Four statistically significant parameters including glucose, peptone , initial pH and liquid volume were selected and utilized in order to optimize the process. The optimized levels of these factors were defined by response surface analysis ( RSA) . The optimized medium and conditions of producing enzyme were obtained. When the strain was cultured with the medium containing 15g/L glucose, 12 g/L peptone , 5g/L NaCl, 0. 2 g/L MgSO4 · 7H2O, 0. 5g/L K2 HPO4 · 3H2O, 1g/L CHsN · HCl, initial pH6. 5, enzyme activity was 32. 68 U/mL.
展开▼
