title: Improved propionic acid production with metabolically engineered Propionibacterium jensenii by an oxidoreduction potential-shift control strategy.
abstract: In this study, a three-stage oxidoreduction potential (ORP) control strategy was developed to improve propionic acid (PA) production using engineered Propionibacterium jensenii ATCC 4868 (pZGX04-gldA) in a 3-L bioreactor. Specifically, ORP was controlled at -200mV from 0 to 36h, -300mV from 36 to 156h, and -400mV after 156h. The PA titer increased from 21.38 to 27.31g/L. The effects of ORP regulation on key intracellular metabolites were studied, demonstrating that ORP can both regulate NADH/NAD(+) ratio and the activities of some enzymes involved in electron transport and redistribute metabolic flux. We integrated the ORP control strategy with a fed-batch culture method and increased PA production to 39.53g/L. This new ORP control strategy may be useful in the optimization of other anaerobic processes.
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, Wuxi 214122, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhuge
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, Wuxi 214122, China.
authors.forename: Jianghua
authors.initials: J
authors.lastname: Li
authors.affiliation: School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta 30332, USA.
authors.forename: Hyun-Dong
authors.initials: HD
authors.lastname: Shin
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, Wuxi 214122, China. Electronic address: longliu@jiangnan.edu.cn.
authors.forename: Long
authors.initials: L
authors.lastname: Liu
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, Wuxi 214122, China. Electronic address: gcdu@jiangnan.edu.cn.
authors.forename: Guocheng
authors.initials: G
authors.lastname: Du
authors.affiliation: Synergetic Innovation Center of Food Safety and Nutrition, Wuxi 214122, China; National Engineering of Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
mesh_terms: D061249:Batch Cell Culture Techniques / Q000295:instrumentation; D019149:Bioreactors / Q000382:microbiology; D007218:Industrial Microbiology / Q000295:instrumentation / Q000379:methods*; D060847:Metabolic Engineering / Q000379:methods*; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D011422:Propionates / Q000378:metabolism*; D011424:Propionibacterium / Q000235:genetics / Q000378:metabolism*
chemical_list: D011422:Propionates; D009243:NAD; C029658:propionic acid
keywords: NADH/NAD(+); ORP-shift control strategy; Oxidoreduction potential; Propionibacterium jensenii; Propionic acid