초록
<P>Development of a designed coculture that can achieve aerotolerant ethanogenic biofuel production from cellulose can reduce the costs of maintaining anaerobic conditions during industrial consolidated bioprocessing (CBP). To this end, a strain of <I>Caldibacillus debilis</I> isolated from an air-tolerant cellulolytic consortium which included a <I>Clostridium thermocellum</I> strain was characterized and compared with the <I>C. debilis</I> type strain. Characterization of isolate <I>C. debilis</I> GB1 and comparisons with the type strain of <I>C. debilis</I> revealed significant physiological differences, including (i) the absence of anaerobic metabolism in the type strain and (ii) different end product synthesis profiles under the experimental conditions used. The designed cocultures displayed unique responses to oxidative conditions, including an increase in lactate production. We show here that when the two species were cultured together, the noncellulolytic facultative anaerobe <I>C. debilis</I> GB1 provided respiratory protection for <I>C. thermocellum</I>, allowing the synergistic utilization of cellulose even under an aerobic atmosphere.</P>