Biohydrogen production by Ethanoligenens harbinense B49: Nutrient optimization

Abstract

A new hydrogen-producing bacterial strain Ethanoligenens harbinense B49 was examined for its capability of H 2 production with glucose as sole carbon source. The H 2 production was significantly affected by the concentration of the yeast powder and phosphate in the synthetic medium. The optimized concentration of yeast powder was 0.3–0.5 g/L and the maximum hydrogen yield was obtained at the concentration of phosphate about 100–150 mmol/L. The dynamics of hydrogen production showed that rapid evolution of hydrogen appeared to start after the middle-phase of exponential growth (about 8 h). The maximum H 2 yield and specific hydrogen production rate were estimated to be 2.26 mol H 2/mol glucose and 27.74 mmol H 2/g cell, respectively, when 10 g/L of glucose was present in the medium. The possible pathway of hydrogen production by Ethanoligenens sp. B49 during glucose fermentation was oxidative decarboxylation of pyruvate and the NADH pathway.