Two-Step Production of Phenylpyruvic Acid from L-Phenylalanine by Growing and Resting Cells of Engineered Escherichia coli: Process Optimization and Kinetics Modeling
Phenylpyruvic acid (PPA) is widely used in the pharmaceutical, food, and chemical industries. Here, a two-step bioconversion process, involving growing and resting cells, was established to produce PPA from l-phenylalanine using the engineered Escherichia coli constructed previously. First, the biotransformation conditions for growing cells were optimized (l-phenylalanine concentration 20.0 g·L−1, temperature 35°C) and a two-stage temperature control strategy (keep 20°C for 12 h and increase the temperature to 35°C until the end of biotransformation) was performed. The biotransformation conditions for resting cells were then optimized in 3-L bioreactor and the optimized conditions were as follows: agitation speed 500 rpm, aeration rate 1.5 vvm, and l-phenylalanine concentration 30 g·L−1. The total maximal production (mass conversion rate) reached 29.8 ± 2.1 g·L−1 (99.3%) and 75.1 ± 2.5 g·L−1 (93.9%) in the flask and 3-L bioreactor, respectively. Finally, a kinetic model was established, and it was revealed that the substrate and product inhibition were the main limiting factors for resting cell biotransformation.
Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China;Synergetic Innovation of Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, China;Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China;Synergetic Innovation of Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, China;Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China;Synergetic Innovation of Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, China;School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta 30332, Georgia, United States of America;Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China;Synergetic Innovation of Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, China;Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China;Synergetic Innovation of Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, China;Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China;Synergetic Innovation of Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, China
Recommended Citation:
Ying Hou,Gazi Sakir Hossain,Jianghua Li,et al. Two-Step Production of Phenylpyruvic Acid from L-Phenylalanine by Growing and Resting Cells of Engineered Escherichia coli: Process Optimization and Kinetics Modeling[J]. PLOS ONE,2016-01-01,11(11)