Evaluation of the addition of glycerol to cupriavidus necator culture medium over poly(3-hydroxybutyrate) production

Abstract

Glycerol was used as a source of additional carbon in the production of Poly(3-hydroxybutyrate) (P(3HB)). The inverted sugar and glycerol concentrations and the temperature of the Cupriavidus necator culture medium were evaluated using a Central Composite Rotational Design (CCRD). The results showed that the increase in temperature and sugar concentration led to an increase in production and P(3HB) accumulation and when 15 g L-1 of glycerol was added better results were obtained, however these were not considered statistically significant. The best results were obtained at 38 °C and with 30 g L-1 of inverted sugar. Although not considered statistically significant, the addition of 15 g L-1 of glycerol increased the P(3HB) accumulation percentage by 15 %, thus in kinetic terms, greater productivity was obtained in 0.32 g L-1 h-1 polymer. Larger scale assays are being conducted to verify if the addition of glycerol improves the thermal and mechanical properties of the synthesized polymer.