title: Efficient biosynthesis of (2S)-pinocembrin from d-glucose by integrating engineering central metabolic pathways with a pH-shift control strategy.
abstract: Microbial fermentations promise to revolutionize the conventional extraction of (2S)-pinocembrin from natural plant sources. Previously an Escherichia coli fermentation system was developed for one-step (2S)-pinocembrin production. However, this fermentation platform need supplementation of expensive malonyl-CoA precursor malonate and requires morpholinopropane sulfonate to provide buffering capacity. Here, a clustered regularly interspaced short palindromic repeats interference was constructed to efficiently channel carbon flux toward malonyl-CoA. By exploring the effects of different culture pH on microbial fermentation, it was found that high pH values favored upstream pathway catalysis, while low pH values favored downstream pathway catalysis. Based on this theory, a two-stage pH control strategy was proposed. The pH was controlled at 7.0 during 0-10h, and was shifted to 6.5 after 10h. Finally, the (2S)-pinocembrin titers increased to 525.8mg/L. These results were attained in minimal medium without additional precursor supplementation, thus offering opportunities for industrial scale low-cost production of flavonoids.
authors.affiliation: College of Food Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Institute of Agro-Product Processing, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu 210095, China.
authors.forename: Junjun
authors.initials: J
authors.lastname: Wu
authors.affiliation: College of Food Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Institute of Agro-Product Processing, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu 210095, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China.
authors.forename: Jingwen
authors.initials: J
authors.lastname: Zhou
authors.affiliation: College of Food Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Institute of Agro-Product Processing, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu 210095, China. Electronic address: dongms@njau.edu.cn.
authors.forename: Mingsheng
authors.initials: M
authors.lastname: Dong
mesh_terms: D004926:Escherichia coli / Q000378:metabolism; D005285:Fermentation; D044950:Flavanones / Q000096:biosynthesis*; D005947:Glucose / Q000737:chemistry* / Q000378:metabolism*; D008316:Malonyl Coenzyme A / Q000378:metabolism; D053858:Metabolic Networks and Pathways
chemical_list: D044950:Flavanones; D008316:Malonyl Coenzyme A; C016063:pinocembrin; D005947:Glucose
keywords: CRISPRi; Gene repressing; Low-cost production; Microorganisms; Plant natural products