Synthesis of polyhydroxyalkanates from waste glycerol obtained in the production of biodiesel
Polimery 2011, No 2, 108
The recent developments in the synthesis of biodegradable polymers especially polyhydroxyacids (PHA) have been reviewed. The advantages of the application, in this type of processes, of mixed microbial cultures (activated sludge) instead of pure cultures of bacteria in order to reduce production costs has also been emphasized. Studies on the synthesis of PHA from waste fractions of glycerol obtained in the production of biodiesel in the presence of mixed microbial cultures have been presented in this paper. The influence of the initial concentrations of such fractions on the efficiency of PHA biosynthesis by the mixed microbial cultures cultivated under anaerobic-aerobic conditions (Table 1, 2, Figs. 1, 2) was evaluated. The highest biopolymer concentration obtained in relation to the dry weight of the cell was 45 %. Copolymers of 3-hydroxybutyric (3HB) and 3-hydroxyvalerian (3HV) acid containing a 15 % of 3HV were the main products synthesized by the cultivated bacteria. The properties of the obtained copolymer were compared to those of synthetic polyolefins (Table 3).