Optimization of fermentation process for metabolic engineered recombinant bacteria with methylenetetrahydrofolate reductase gene / 中国药学杂志

ABSTRACT

OBJECTIVE: The fermentation process for the metabolic engineered recombinant bacteria with methylenetetrahydrofolate reductase gene was optimized to improve L-5-methyltetrahydrofolate accumulation in the engineering bacteria. METHODS: Single- factor and orthogonal experiments were employed to investigate the optimum fermentation process of the bacteria. RESULTS: The optimum fermentation process of the bacteria was as following: sucrose was 3%, yeast extract was 1.0%, inorganic salts were NaCl-K2HPO4-MgSO4 = 1.26%:0.42%:0.02%, ammonium dihydrogen phosphate was 1.0%, inoculum amount was 5%, initial pH value was 7.5, induction time point was 2.5 h, inducer concentration was 1.4 mmol·L-1, incubation temperature was 37°C, induction duration was 6 h, addition degree of inducer was 2. Under the optimum fermentation process, the optimization results were as following: the bacteria amount had a 36.4% enhancement, the specific activity of methylenetetrahydrofolate reductase 46.8%, the L-5-methyltetrahydrofolate accumulation 66.1%, comparing with the original fermentation process. CONCLUSION: The research work provides experimental evidence for amplifying of the bacteria in agitating fermentor.