Tailor‐Made Polyhydroxyalkanoates by Reconstructing Pseudomonas Entomophila

Microbial polyhydroxyalkanoates (PHA) containing short‐ and medium/long‐chain‐length monomers, abbreviated as SCL‐co‐MCL/LCL PHAs, generate suitable thermal and mechanical properties. However, SCL‐co‐MCL/LCL PHAs with carbon chain longer than nine are difficult to synthesize due to the low specificity of PHA synthase PhaC and the lack of either SCL‐ or MCL/LCL monomer precursor fluxes. This study succeeds in reprogramming a β‐oxidation weakened Pseudomonas entomophila containing synthesis pathways of SCL 3‐hydroxybutyryl‐CoA (3HB) from glucose and MCL/LCL 3‐hydroxyalkanoyl‐CoA from fatty acids with carbon chain lengths from 9 to 18, respectively, that are polymerized under a low specificity PhaC61‐3 to form P(3HB‐co‐MCL/LCL 3HA) copolymers. Through rational flux‐tuning approaches, the optimized recombinant P. entomophila accumulates 55 wt% poly‐3‐hydroxybutyrate in 8.4 g L−1 cell dry weight. Combined with weakened β‐oxidation, a series of novel P(3HB‐co‐MCL/LCL 3HA) copolymers with over 60 wt% PHA in 9 g L−1 cell dry weight have been synthesized for the first time. P. entomophila has become a high‐performing platform to generate tailor‐made new SCL‐co‐MCL/LCL PHAs.