초록
The effects of Fe<SUP>2+</SUP>, Mg<SUP>2+</SUP> ions and l-cysteine on hydrogen production and cell growth of Clostridium beijerinckii RZF-1108 were investigated, and [FeFe]-hydrogenase (hydA) gene expression under different conditions was evaluated using quantitative reverse transcription PCR (qRT-PCR). Best concentration of Fe<SUP>2+</SUP> stimulated hydrogen production, cell biomass and hydA gene expression in C. beijerinckii RZF-1108. Mg<SUP>2+</SUP> increased cell growth and hydrogen evolution, but negatively facilitated hydrogen production rate and hydA gene expression. l-cysteine slightly stimulated hydA gene expression, but not hydrogen production in strain RZF-1108. A maximum hydrogen yield of 1.96 mol H<SUB>2</SUB>/mol glucose and production rate of 106.0 ml H<SUB>2</SUB>/l medium.h<SUP>-1</SUP> were obtained using optimized culture medium supplemented with 0.2 g/l FeSO<SUB>4</SUB>.7H<SUB>2</SUB>O and 0.1 g/l MgCl<SUB>2</SUB>.6H<SUB>2</SUB>O. These experimental results suggested that the effects of metal ions on hydrogen production by C. beijerinckii RZF-1108 was complicated. Hydrogen production was highly dependent on the cooperation of cell growth and hydrogenase gene expression.