Strategies of biosynthesis of poly(3-hydroxybutyrate) supplemented with biodiesel obtained from rice bran oil

The persistence of conventional synthetic plastic in the environment is increasingly considered as a source of ecological problem and has been motivated the research of biodegradable and biocompatible polymers. Polyhydroxyalkanoates (PHAs) are thermoplastic polyesters synthesized by several bacteria and Cupriavidus necator is the known one. Due to the high production cost of PHAs, the use of a cheaper carbon source or nutritional supplements are required in order to reduce the production cost. The aim of this research was to investigate the influence of biodiesel of rice bran oil as a low cost nutritional supplement in cultures of C. necator in mineral medium on the cell growth and production of poly(3-hydroxybutyrate) - P(3HB). For this, C. necator was cultivated in shake flasks of 500 mL with 150 mL of mineral medium at 30 °C for 24 h in 150 rpm. Samples were removed each 4 h for evaluation. The results demonstrate that the addition of biodiesel of rice bran oil as nutritional supplement in the culture of C. necator was viable, since its addition allows a cell growth with substrate consume reduction. Besides, the P(3HB) yield was 61% and 150% superior when biodiesel was used compared to the control medium using 30 g L− 1 and 15 g L− 1, respectively.