Metabolic engineering of Halomonas bluephagenesis for production of five carbon molecular chemicals derived from L-lysine
Fang Yang, Huan Wang, Cuihuan Zhao, Lizhan Zhang, Xu Liu, Helen Park, Yiping Yuan, Jianwen Ye, Qiong Wu, Guo‐Qiang Chen
Abstract
5-Aminovaleric acid (5-AVA), 5-hydroxyvalerate (5HV), copolymer P(3HB- co -5HV) of 3 -hydroxybutyrate (3HB) and 5HV were produced from L-lysine as a substrate by recombinant Halomonas bluephagenesis constructed based on codon optimization, deletions of competitive pathway and L-lysine export protein, and three copies of davBA genes encoding L-lysine monooxygenase (DavB) and 5-aminovaleramide amidohydrolase (DavA) inserted into its genome to form H. bluephagenesis YF117Δ gabT 1+2 , which produced 16.4 g L −1 and 67.4 g L −1 5-AVA in flask cultures and in 7 L bioreactor , respectively. It was able to de novo synthesize 5-AVA from glucose by L-lysine-overproducing H. bluephagenesis TD226. Corn steep liquor was used instead of yeast extract for cost reduction during the 5-AVA production. Using promoter engineering based on P porin mutant library for downstream genes, H. bluephagenesis YF117 harboring pSEVA341-P porin 42 - yqhD EC produced 6 g L −1 5HV in shake flask growth , while H. bluephagenesis YF117 harboring pSEVA341-P porin 42 - yqhD EC -P porin 278 - phaC RE -abfT synthesized 42 wt% P(3HB- co -4.8 mol% 5HV) under the same condition. Thus, H. bluephagenesis was successfully engineered to produce 5-AVA and 5HV in supernatant and intracellular P(3HB- co -5HV) utilizing L-lysine as the substrate.