Synthesis of tunable copolymers of 3-hydroxybutyrate and 3-hydroxyvalerate by engineered Halomonas bluephagenesis and their characterizations

作者：Shaowei Li, Jinghui Wang, Yaoyao Zhang, Kaixin Du, Jiangnan Chen, Jianping Sun, Huan Wang, Pengfei Ouyang, Xuanming Xu, Fuqing Wu, Fang Yang, Guo‐Qiang Chen · 发表于：Synthetic and Systems Biotechnology · 年份：2025 · DOI：10.1016/j.synbio.2025.11.007 · 被引用次数：2 · 研究领域：biodegradable polymer synthesis and properties、Microbial Metabolic Engineering and Bioproduction、Carbon dioxide utilization in catalysis

Poly(3-hydroxybutyrate- co -3-hydroxyvalerate) (PHBV) with a 0–30 mol% controllable range of 3HV ratios was produced by Halomonas bluephagenesis ( H. bluephagenesis ) and characterized. An endogenous plasmid containing scpA and scpB encoding methylmalonyl-CoA epimerase and methylmalonyl-CoA decarboxylase, respectively, redirects succinyl-CoA toward propionyl-CoA, enabling de novo PHBV synthesis with a 1.7 mol% 3HV. Deletion of sdhE and prpC encoding succinate dehydrogenase and 2-methylcitrate synthase, respectively, further enhanced the 3HV to 4 mol%. H. bluephagenesis GZ05 was engineered for late-phase-specific MreB (a cytoskeletal protein) degradation, enlarged intracellular PHBV granules for enhanced PHBV synthesis, and convenient downstream. A series of growth experiments was conducted in a 7 L bioreactor fed with valerate to produce PHBV with various 3HV molar ratios (2–27 mol%). A quantitative relationship between valerate concentration and the final 3HV molar ratio was established with an R 2 = 0.9833, enabling precise control of the 3HV ratio in PHBV. H. bluephagenesis GZ05 was grown to 100 g L −1 cell dry weight (CDW) containing 73 wt% PHBV consisting of 1.6 mol% 3HV in a 5000 L bioreactor. Thermal analysis demonstrated enhanced flexibility with higher 3HV content in PHBV.