Optimization of culture conditions for hydrogen production by Ethanoligenens harbinense B49 using response surface methodology

The design of an optimum and cost-efficient medium for high-level production of hydrogen by Ethanoligenens harbinense B49 was attempted by using response surface methodology (RSM). Based on the Plackett–Burman design, Fe2+ and Mg2+ were selected as the most critical nutrient salts. Subsequently, the optimum combination of the selected factors and the sole carbon source glucose were investigated by the Box–Behnken design. Results showed that the maximum hydrogen yield of 2.21 mol/mol glucose was predicted when the concentrations of glucose, Fe2+ and Mg2+ were 14.57 g/L, 177.28 mg/L and 691.98 mg/L, respectively. The results were further verified by triplicate experiments. The batch reactors were operated under an optimized condition of the respective glucose, Fe2+ and Mg2+ concentration of 14.5 g/L, 180 mg/L and 690 mg/L, the initial pH of 6.0 and experimental temperature of 35 ± 1 oC. Without further pH adjustment, the maximum hydrogen yield of 2.20 mol/mol glucose was obtained based on the optimized medium with further verified the practicability of this optimum strategy.