2025/06/06 by Ju Wu, Xuan Gong, Pengye Guo +3 · 1 voice
Materials Science · Environmental Science · Biochemistry, Genetics and Molecular Biology · #biodegradable polymer synthesis and properties #Microplastics and Plastic Pollution #Biopolymer Synthesis and Applications
paper · doi:10.1016/j.bidere.2025.100027
openalex publication_date 2025/06/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
In this study, a platform was constructed for the efficient biosynthesis of a lactate-based copolymer using a phosphite dehydrogenase (PtxD)-based NADH regeneration strategy. PtxD catalyzes the conversion of phosphite to phosphate while reducing NAD + to NADH. The latter is an essential cofactor for lactate synthesis in Escherichia coli . This strategy allows the decoupling of NADH regeneration from carbon metabolism flow, providing sufficient NADH for lactate synthesis. Different concentrations of isopropyl β-d-1-thiogalactopyranoside (IPTG) were used to control the intensity of PtxD expression, and the lactate fraction in the copolymer synthesized by the engineered strain ranged from 6.2–16.7 mol%. The ptxD gene was integrated into the genome of strain WJPCTP-01, which successfully synthesized 3.24 g/L P(3HB- co -23.0 mol% LA) and 2.23 g/L P(3HB- co -39.0 mol% LA) using glucose and xylose as substrates, respectively, in shake flask cultures. In 5 L bioreactor fermentations, the titer of P(3HB- co -41.3 mol% LA) reached 8.57 g/L, with a synthesis rate of 0.12 g/L/h when xylose was used as a substrate. These findings indicate that the PtxD-based NADH regeneration strategy enhances lactate synthesis without any significant negative impact on bacterial growth or the synthesis of P(3HB- co -LA).