초록
Cheese whey powder (CWP) solution was used as the raw material for hydrogen gas production by mesophilic (35 <SUP>o</SUP>C) and thermophilic (55 <SUP>o</SUP>C) dark fermentations at constant initial total sugar and bacteria concentrations. Thermophilic fermentation yielded higher cumulative hydrogen formation (CHF = 171 mL), higher hydrogen yield (111 mL H<SUB>2</SUB> g<SUP>-1</SUP> total sugar), and higher hydrogen formation rate (3.46 mL H<SUB>2</SUB> L<SUP>-1</SUP> h<SUP>-1</SUP>) as compared to mesophilic fermentation. CHF in both cases were correlated with the Gompertz equation and the constants were determined. Despite the longer lag phase, thermophilic fermentation yielded higher specific H<SUB>2</SUB> formation rate (2.10 mL H<SUB>2</SUB> g<SUP>-1</SUP>cells h<SUP>-1</SUP>). Favorable results obtained in thermophilic fermentation were probably due to elimination of H<SUB>2</SUB> consuming bacteria at high temperatures and selection of fast hydrogen gas producers.