Cellulose hydrolysis and ethanol production by a facultative anaerobe bacteria consortium H and its identification

Abstract:

The recalcitrance of lignocellulosic biomass makes its hydrolysis by cellulases less effective, and the consolidated bioprocessing (CBP) strategy that combines enzyme production, cellulose hydrolysis and fermentation, particularly the synergetic role of different microbes in attacking cellulose component could be a solution. In this article, a facultative anaerobe microbial consortium named H was isolated, which exhibited high stability even after 30 subcultures, with pH ranging from 6 to 9. Within three days, 0.5 g filter paper immerged in 100 mL PCS buffer was completely degraded, and 1.54 g/L ethanol was produced, correspondingly. Further analysis on the component of the microbe consortium was carried out though 16S rDNA and DGGE, and Clostridium thermosuccinogene, Clostridium straminisolvens and Clostridium isatidis that can directly convert cellulose to ethanol were identified, indicating that Clostridium spp. played important role in cellulose degradation through the synergistic coordination of different species, and the characterization of the consortium will benefit the analysis of the underlying mechanisms as well as the optimization of the CBP process for more efficient cellulose degradation and ethanol production.