Synthesis of poly(3-hydroxybutyrate) by the autotrophic CO-oxidizing bacterium Seliberia carboxydohydrogena Z-1062

The present study addresses growth parameters and physiological and biochemical characteristics of the aerobic CO-oxidizing carboxydobacterium Seliberia carboxydohydrogena Z-1062. Poly(3-hydroxybutyrate) yields were investigated in experiments with limiting concentrations of mineral nutrients (nitrogen or sulfur or nitrogen and sulfur) in batch culture of S. carboxydohydrogena Z-1062 grown on gas mixtures consisting of CO(2), O(2), H(2), and CO. CO concentrations of 10, 20, and 30 % v/v did not affect polymer synthesis, whose content after 56-h cultivation under limiting concentrations of nitrogen and sulfur was 52.6-62.8 % of biomass weight at a productivity of 0.13-0.22 g/L h. The inhibitory effect of CO on cell concentration was revealed at CO concentration of 30 % v/v. That also caused a decrease in substrate (H(2) and O(2)) use efficiency. Thus, this carboxydobacterium can be regarded as a potential producer of polyhydroxyalkanoates from industrial hydrogenous sources.