Production of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) by Recombinant Pseudomonas stutzeri 1317 from Unrelated Carbon Sources

Synthetic biology promises to simplify the construction of metabolic pathways by assembling the detached modules of the whole pathway. This gives new approaches for the microbial production of industrial products such as polyhydroxyalkanoates (PHA). In this study, to produce poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) by Pseudomonas stutzeri 1317 from unrelated carbon sources such as glucose, the phaC1-phaZ-phaC2 operon of P. stutzeri 1317 was knocked out to generate the PHA deficient mutant P. stutzeri 1317LF. Then three modules containing phaCAhAReBRe, phaCAhBReGPp and phaCAhPAh were introduced into P. stutzeri 1317LF separately. The shake flask results indicated that the precursor supply and PHA synthase activity were the vital factors for the PHBHHx accumulation of P. stutzeri 1317LF. Furthermore, the PHBHHx accumulation of the recombinants from different carbon resources were performed. The highest PHBHHx content was 23.7% (by mass) with 58.6% (by mole) 3HB fraction. These results provide basis for further improving the PHBHHx accumulation of P. stutzeri from unrelated carbon sources.