초록
<P><B>Abstract</B></P> <P>A newly isolated strain <I>Enterococcus faecium</I> INET2 was used as inoculum for biohydrogen production through dark fermentation. The individual and interactive effect of initial pH, operation temperature, glucose concentration and inoculation amount on the accumulation of hydrogen during fermentation was examined by a Box–Behnken Design (BBD), and hydrogen production process was analyzed at the optimal condition. A significant interactive effect between glucose concentration and pH was observed, the optimal condition was initial pH 7.1, operation temperature 34.8 °C, glucose concentration 11.3 g/L and inoculation amount 10.4%. Hydrogen yield, maximum hydrogen production rate and hydrogen production potential were determined to be 1.29 mol H<SUB>2</SUB>/mol glucose, 86.7 L H<SUB>2</SUB>/L/h and 1.35 L H<SUB>2</SUB>/L. Metabolites analysis showed that <I>E. faecium</I> INET2 followed the pyruvate: formate lyase (Pfl) pathway in first 16 h, followed by the acetate-type fermentation and then shifted to butyrate-type fermentation. Maximum hydrogen production rate was accompanied with a quick formation of acetic acid.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel strain <I>Enterococcus faecium</I> INET2 was used for hydrogen production. </LI> <LI> The conditions for hydrogen production were optimized. </LI> <LI> The interactive effect between pH and substrate concentration was significant. </LI> <LI> <I>E. faecium</I> INET2 followed pyruvate: formate lyase (Pfl) pathway in first 16 h. </LI> </UL> </P>