高产靛蓝色素大肠杆菌基因工程菌的构建及其发酵条件优化

Construction of Genetically Engineered E. coli and Optimization of Its Fermentation Conditions for High-Level Production of Indigo

通过基因重组技术构建重组苯乙烯单加氧酶基因的高产靛蓝色素大肠杆菌基因工程菌Escherichia coli AB,研究优化工程菌E.coli AB生物合成靛蓝色素的发酵条件。单因素试验分别考察不同发酵温度、底物质量浓度、起始pH值和接种量4个因素对于靛蓝色素合成的影响,选取发酵温度、底物浓度和起始pH值3个对靛蓝色素产量影响显著的因素进行响应面设计试验优化。经模型分析获得优化发酵条件为:底物质量浓度0.95 mg/m L,发酵温度29℃,起始pH 6.9。在该条件下,工程菌E.coli AB催化合成靛蓝色素产量为67.65 mg/m L。优化发酵条件的实验结果与预测值相符,说明回归模型切实可行。

A genetically engineered strain of Escherichia coli for the expression of the styrene monooxygenase gene from Pseudomonas putida was constructed by recombinant DNA technique, and the fermentation conditions of the recombinant strain were optimized for enhanced indigo production. Firstly, the effects of four factors including substrate concentration, fermentation temperature, initial pH and inoculum amount on indigo production were investigated. Then, the response surface methodology was applied to optimize the variables showing significant influence on indigo production, substrate concentration, fermentation temperature and initial pH. Results revealed that the optimized fermentation conditions were determined as substrate concentration of 0.95 mg/m L, fermentation temperature of 29 ℃ and initial pH 6.9. The predicted indigo production was 67.65 mg/m L, which was in close agreement with the predicted value, indicating that the model was feasible.