High production of poly(3-hydroxybutyrate) in Escherichia coli using crude glycerol

• Published in: Bioresource technology Vol. 384; p. 129315
• Main Authors: Ta, Doan-Thanh, Chiang, Chung-Jen, Huang, Zhu-Xuan, Luu, Nguyen-Luan, Chao, Yun-Peng
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.09.2023
• Subjects: 3-Hydroxybutyric Acid - metabolism; Crude glycerol; Escherichia coli - genetics; Escherichia coli - metabolism; Glycerol - metabolism; Hydroxybutyrates - metabolism; Metabolic engineering; Plastics - metabolism; Poly(3-hydroxybutyrate); Polyesters - metabolism; PP; TCA; CDW; Poly(3-hydroxybutyrate); PHA; Metabolic engineering; Crude glycerol; PHB; DO
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2023.129315

[Display omitted] •Development of the PHB-producing Escherichia coli strain based on crude glycerol.•Improvement of the producer strain by rewiring central metabolism.•Implementation of fed-batch fermentation for high PHB titer, content, and productivity. Poly(3-hydroxybutyrate) (PHB) is a prominent bio-plastic and recognized as the potential replacement of petroleum-derived plastics. To make PHB cost-effective, the production scheme based on crude glycerol was developed using Escherichia coli. The heterogeneous synthesis pathway of PHB was introduced into the E. coli strain capable of efficiently utilizing glycerol. The central metabolism that links to the synthesis of acetyl-CoA and NADPH was further reprogrammed to improve the PHB production. Key genes were targeted for manipulation, involving those in glycolysis, the pentose phosphate pathway, and the tricarboxylic cycle. As a result, the engineered strain gained a 22-fold increase in the PHB titer. Finally, the fed-batch fermentation was conducted with the producer strain to give the PHB titer, content, and productivity reaching 36.3 ± 3.0 g/L, 66.5 ± 2.8%, and 1.2 ± 0.1 g/L/h, respectively. The PHB yield on crude glycerol accounts for 0.3 g/g. The result indicates that the technology platform as developed is promising for the production of bio-plastics.