Influence of carbonates and phosphates on fermentative biohydrogen production of Biohydrogenbacterium R3 sp. nov.

This study investigated the effects of phosphates and carbonates (NH₄HCO₃, NaHCO₃, Na₂CO₃, K₂HPO₄, KH₂PO₄, NaH₂PO₄ and Na₂HPO₄) on the hydrogen production efficiency and cell growth to Biohydrogenbacterium R3 sp.nov. It was indicated that the carbonates could buffer the pH in reactor better and the phosphates could promote the hydrogen production obviously. When Na₂HPO₄ and K₂HPO₄ were added into the reactor, the hydrogen production and content reached the maximum of 1978.56 mL, 44.1% and 2160.9 mL, 45.8%, respectively. The pH and cell weight achieved 3.28, 1.03 g·L^-1 and 3.41, 1.21 g·L^-1, respectively. When Na₂HPO₄ was added into the reactor, the ethanol and acetic acid were 4841.49 mg·L^-1 and 2064.94 mg·L^-1, respectively, while when Na₂CO₃ was added into the reactor, the hydrogen production, hydrogen content, cell weight, pH, ethanol and acetic acid were 1064.42 mL, 35.96%, 1.23 g·L^-1, 3.81, 3862.21 mg·L^-1 and 1930.86 mg·L^-1, respectively.