초록
<P>This study was demonstrated with a coculture fermentation system using sugar beet pulp (SBP) as a carbon source combining the cellulose-degrading bacterium <I>Clostridium cellulovorans</I> with microbial flora of methane production (MFMP) for the direct conversion of cellulosic biomass to methane (CH<SUB>4</SUB>). The MFMP was taken from a commercial methane fermentation plant and extremely complicated. Therefore, the MFMP was analyzed by a next-generation sequencing system and the microbiome was identified and classified based on several computer programs. As a result, <I>Methanosarcina mazei</I> (1.34% of total counts) and the other methanogens were found in the MFMP. Interestingly, the simultaneous utilization of hydrogen (H<SUB>2</SUB>) and carbon dioxide (CO<SUB>2</SUB>) for methanogenesis was observed in the coculture with Consortium of <I>C. cellulovorans</I> with the MFMP (CCeM) including <I>M. mazei</I>. Furthermore, the CCeM degraded 87.3% of SBP without any pretreatment and produced 34.0 L of CH<SUB>4</SUB> per 1 kg of dry weight of SBP. Thus, a gas metabolic shift in the fermentation pattern of <I>C. cellulovorans</I> was observed in the CCeM coculture. These results indicated that degradation of agricultural wastes was able to be carried out simultaneously with CH<SUB>4</SUB> production by <I>C. cellulovorans</I> and the MFMP.</P>