초록
<P><B>Abstract</B></P> <P>Thermophilic hydrogen fermentation of cellulose was evaluated by a long term continuous experiment and batch experiments. The continuous experiment was conducted under 55 °C using a continuously stirred tank reactor (CSTR) at a hydraulic retention time (HRT) of 10 day. A stable hydrogen yield of 15.4 ± 0.23 mol kg<SUP>−1</SUP> of cellulose consumed was maintained for 190 days with acetate and butyrate as the main soluble byproducts. An analysis of the 16S rRNA sequences showed that the hydrogen-producing thermophilic cellulolytic microorganisms (HPTCM) were close to <I>Thermoanaerobacterium thermosaccharolyticum</I>, <I>Clostridium</I> sp. and <I>Enterobacter cloacae</I>. Batch experiment demonstrated that the highest H<SUB>2</SUB> producing activity was obtained at 55 °C and the ultimate hydrogen yield and the metabolic by-products were influenced greatly by temperatures. The effect of temperature variation showed that the activation energy for cellulose and glucose were estimated at 103 and 98.8 kJ mol<SUP>−1</SUP>, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Continuous cellulosic-hydrogen fermentation was conducted at 55 °C. </LI> <LI> Hydrogen yield was improved to 15.4 mol kg<SUP>−1</SUP> of consumed-cellulose. </LI> <LI> The cellulosic hydrogen bacteria were close to <I>Clostridia</I> and <I>Enterobacter</I> genus. </LI> <LI> The mixed microflora produced H<SUB>2</SUB> within a wide range of temperatures (35 °C–65 °C). </LI> <LI> Activation energy of cellulose and glucose were 103 and 98.8 kJ mol<SUP>−1</SUP>, respectively. </LI> </UL> </P>