High yield production of polyhydroxyalkanoates from soybean oil by Ralstonia eutropha and its recombinant strain

Abstract

High yield production of polyhydroxyalkanoates (PHAs) by Ralstonia eutropha H16 and its recombinant strain PHB−4/pJRDEE32d13 (a PHA-negative mutant harboring Aeromonas caviae PHA synthase gene, phaCAc) from renewable inexpensive soybean oil was investigated. The PHA production by the wild-type strain H16 was achieved with a high dry cells weight (118–126 g/l) and a high poly[(R)-3-hydroxybutyrate] [P(3HB)] content per dry cells of 72–76% (w/w). A copolymer of 3HB with 5 mol% (R)-3-hydroxyhexanoate, P(3HB-co-5 mol% 3HHx), could be produced from soybean oil as a sole carbon source by the recombinant strain PHB−4/pJRDEE32d13 with a high dry cells weight (128–138 g/l) and a high PHA content of 71–74% (w/w). The reproducible results of PHA production in the presence of soybean oil as a sole carbon source was obtained with a high yield at a range of 0.72 to 0.76 g-PHA per g-soybean oil used.