Sugarcane molasses and vinasse as a substrate for polyhydroxyalkanoates (PHA) production

Abstract

Polyhydroxyalkanoates (PHA) are fully biodegradable biopolymers of microbial origin, with physicochemical characteristics similar to those of conventional synthetic plastics. However, their current production is highly expensive mainly due to the substrate or culture medium employed. In this research, a mixture of cane molasses and residual vinasse from the alcohol industry was evaluated as a substrate using the reference strain Ralstonia eutropha ATCC 17699 to produce PHAs. The results showed the potential of the mixture as a culture medium, after reaching polymer concentrations of 3.17 g/L in MSM medium and 2.71 g/L in M/V medium with a molasses/vinasse ratio of 25/75. There was a sugar (sucrose, fructose, and glucose) consumption yield of 70.7%, and a biopolymer accumulation of 97.8% with respect to the biomass produced. The biopolymer characterization showed a correlation with the standard polyhydroxybutyrate sample-PHB of 99.25%.