Production and characterization of biodegradable films of a novel polyhydroxyalkanoate (PHA) synthesized from peanut oil

Peanut oil was used as a carbon source for the production of films of a novel polyhydroxyalkanoate (PHA) intended for applications as biodegradable packaging for the food industry. Cupriavidus necator was used in a two-stage production system. In the first stage, bacterial growth was favored and, in the second, PHA was synthesized. The use of 2% (v/v) vegetable oil, rich in saturated fatty acids, allowed a yield of 0.7 g of PHA per g of peanut oil. A heteropolymer of PHA was obtained composed of 98.2 mol% of 3-hydroxybutyrate, 0.75 mol% of 3-hydroxyvalerate and, 1 mol% of medium-length-chain hydroxyalkanoate (HA). The synthesized PHA exhibited a decrease in the melting temperature and an increase in elongation at break in comparison with homopolymer polyhydroxybutyrate (PHB). The water vapour permeability of the PHA film was similar to that of polyethylene terephthalate films. Moreover, the biodegradation in soil of the PHA film was demonstrated exhibiting a weight lost of 75% after 80 days. The properties exhibited by the PHA films could make possible its applications in the food packaging and in the biotechnology industry.