6 2000 1500 4.5 500 3.5 02468101214161820 Time(h) Time course of growth, glucose consumption soluble protein consumption, the composition of fermentation metabolites pH, and hydrogen eⅴ olution• Time course of growth, glucose consumption, soluble protein consumption,the composition of fermentation metabolites pH, and hydrogen evolution 3.5 4 4.5 5 5.5 6 0 2 4 6 8 10 12 14 16 18 20 Time (h) pH 0 500 1000 1500 2000 Cummulative H 2 production(ml/L-culture)