Biobutanol Production from Crystalline Cellulose through Consolidated Bioprocessing

Biobutanol production directly from lignocellulose, known as consolidated bioprocessing (CBP), is expected to be much less expensive than a process where hydrolytic enzyme production, cellulose saccharification, and microbial fermentation are accomplished separately. However, few microbes possess both cellulolytic and solventogenic properties in nature. Current research aims to endow cellulolytic microorganisms with butanol-producing ability or to set up microbial consortia for CBP. This review comprehensively details current achievements attempting to confer butanol-generating ability, not only to cellulolytic Clostridium strains but also to microbial consortia, to address and overcome major challenges in butanol production from cellulose. Recent advances in improving cellulosome activities within cellulolytic Clostridium strains are also emphasized.