响应面分析法优化麦麸酯酶双水相萃取的条件

Optimization of the extraction condition for wheat bran esterase in aqueous two-phase systems by response surface analysis

摘要: 研究采用聚乙二醇/硫酸铵双水相体系萃取麦麸酯酶,通过单因素实验考察不同PEG分子量、PEG浓度、无机盐种类、无机盐浓度、pH和离子强度对麦麸酯酶总蛋白分配系数、酶活回收率、纯化倍数的影响,并通过响应面分析法优化了萃取条件。结果表明最佳萃取条件为:PEG1000质量浓度为21%、(NH4)2SO4质量浓度为18%、pH4.4。回归方程预测双水相萃取纯化倍数可达到2.9208,三次验证实验的平均纯化倍数为2.9190,与预测值相对误差为0.06%。

Abstract: The extraction of wheat bran esterase by aqueous two- phase system composed of PEG / ( NH4) 2SO4was studied.The effects of molecular weight and concentration of polyethylene glycol ( PEG) , the concentration of ( NH4) 2SO4concentration, pH value and NaCl addition etc. on the distribution coefficient, activity yield and purification factor were examined. Response surface methodology was employed to optimize this system. The results showed that the optimum conditions were PEG1000 21% ( m /m) , ( NH) 2SO418% ( m /m) and pH at 4.4.Under these conditions, the purification factor could reach to 2.9208, the average degree of purification factor of three times experiment reach to 2.9190, compared with predictive value the relative error was 0.06%.