Hydrogen and alcohols production by Serratia sp. from an inorganic carbon source

Abstract

Climate change and its consequences have stimulated the development of new bioprocesses to reduce CO2 concentrations. One approach to address this problem is to recycle CO2 directly into biofuels or chemicals using chemolithotrophic bacteria. The objective of this study was to evaluate the hydrogen and alcohols production capacity of a chemolithotrophic bacteria Serratia sp. (MZ413438) using NaHCO3 as the sole carbon source in concentrations of 0, 5, 15, 30, 45 and 60 g L−1. The experimental results showed that the maximum cumulative hydrogen production of 205.00 ± 3.53 mL L−1 was obtained for the treatments at concentrations of 45 g L−1 of NaHCO3. Furthermore, the experimental data on hydrogen production at different NaHCO3 concentrations were fitted to the kinetic Gompertz model. The main alcohols found in the different treatments with NaHCO3 were: ethanol, 1-butanol, 1-propanol, 2-methyl-1-propanol, and 3-methyl-1-butanol. The highest abundance and maximum concentration of alcohols were obtained for the treatments at concentrations of 60 g L−1 of NaHCO3. This study demonstrates the metabolic potential of Serratia sp. (MZ413438) due to its very short times of bicarbonate fixation (8 h) and bioconversion to value-added products such as hydrogen and alcohols, which increases the knowledge of a diverse group of microorganisms with these capacities, including bacteria and archaea.