Metabolic engineering for biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from glucose and propionic acid in recombinant Escherichia coli

• DOI: 10.1016/j.biortech.2022.126786
• Publication Date: 2022-02-01T22:07:11Z
• Authors: Dong Meng; Changfeng Miao; Yuling Liu; Fang Wang; Lu Chen; Zhaosong Huang; Xiangyu Fan; Pengfei Gu; Qiang Li
• Keywords: Thermogravimetric analysis; Valerate; Polyhydroxybutyrate; Thermal Stability; Metabolic Engineering

In this study, novel polyhydroxyalkanoate (PHA)-associated genes (phaCp and phaABp) cloned from Propylenella binzhouense L72T were expressed in Escherichiacoli cells for PHA production, and the recombinant strains were used to analyze PHA yields with various substrates. The highest poly (3-hydroxybutyrate-co-3-hydroxy-valerate) (PHBV) yield (1.06 g/L) and cell dry weight (3.31 g/L) in E. coli DH5α/ΔptsG-CpABp were achieved by using glucose and propionicacid as substrates. Structural verification of PHBV produced by E. coli DH5α/ΔptsG-CpABp was performed to evaluate the characteristics of the polymers using Fourier transform infrared spectroscopy and nuclear magnetic resonance analysis. In addition, the X-ray diffraction results showed improved crystallinity of PHBV, and thermogravimetric analysis showed good thermal stability of 298 °C. The above findings indicated that the expression of phaCp and phaABp genes resulted in improved PHBV synthesis activity, and the polymer had better performance at higher processing temperatures.