LAUSR

Abstract The economic production and wider utilisation of poly(3-hydroxybutyrate) (PHB) is dependent on the development of processes based on alternative, low cost and renewable feedstocks. The purpose of this study is to investigate the suitability of using waste date seed oil extract as an alternative carbon source for PHB synthesis. The extraction of date seed oil using different solvents, a chloroform, methanol mixture (MCM), hexane and petroleum ether (PE) was studied. Results indicate that the MCM gave the highest oil yield of 9.3%, whilst the oil yields obtained using hexane and PE were 5.3% and 3.4%, respectively. This date seed oil was used as the sole carbon source in a series of microbial fermentation experiments, and the results show that PHB is accumulated as a significant percentage of dry cell weight (DCW). A maximum DCW of 14.35 g/l was obtained with a PHB content of 82%, giving a PHB concentration of 11.77 g/l. The molecular structure and thermal properties of the PHB produced were determined by H NMR, DSC and GPC, with results being broadly comparable to those of a PHB standard. Our results demonstrate that date seed oil is a feasible substrate for the production of meaningful amounts of PHB.