초록
<P>Identification, characterization, and end-product synthesis patterns were analyzed in a newly identified mesophilic, anaerobic Clostridium sp. strain URNW, capable of producing hydrogen (H2) and ethanol. Metabolic profiling was used to characterize putative end-product synthesis pathways of the Clostridium sp. strain URNW, which was found to grow on cellobiose; on hexose sugars, such as glucose, sucrose, and mannose; and on sugar alcohols, like mannitol and sorbitol. When grown in batch cultures on 2 g cellobiose·L<SUP>-1</SUP>, Clostridium sp. strain URNW showed a cell generation time of 1.5 h, and the major end-products were H2, formate, carbon dioxide (CO2), lactate, butyrate, acetate, pyruvate, and ethanol. The total volumetric H2production was 14.2 mmol·(L culture)<SUP>-1</SUP>and the total production of ethanol was 0.4 mmol·(L culture)<SUP>-1</SUP>. The maximum yield of H2was 1.3 mol·(mol glucose equivalent)<SUP>-1</SUP>at a carbon recovery of 94%. The specific production rates of H2, CO2, and ethanol were 0.45, 0.13, and 0.003 mol·h<SUP>-1</SUP>·(g dry cell mass)<SUP>-1</SUP>, respectively. BLAST analyses of 16S rDNA and chaperonin 60 (cpn60) sequences from Clostridium sp. strain URNW revealed a 98% nucleotide sequence identity with the 16S rDNA and cpn60 sequences from Clostridium intestinale ATCC 49213. Phylogenetic analyses placed Clostridium sp. strain URNW within the butyrate-synthesizing clostridia.</P>