Cellulase, clostridia, and ethanol.
Biomass conversion to ethanol as a liquid fuel by the thermophilic and anaerobic clostridia offers a potential partial solution to the problem of the world's dependence on petroleum for energy. Coculture of a cellulolytic strain and a saccharolytic strain of Clostridium on agricultural resources, as well as on urban and industrial cellulosic wastes, is a promising approach to an alternate energy source from an economic viewpoint. This review discusses the need for such a process, the cellulases of clostridia, their presence in extracellular complexes or organelles (the cellulosomes), the binding of the cellulosomes to cellulose and to the cell surface, cellulase genetics, regulation of their synthesis, cocultures, ethanol tolerance, and metabolic pathway engineering for maximizing ethanol yield.
Demain
Arnold L
AL
Charles A. Dana Research Institute for Scientists Emeriti, HS-330, Drew University, Madison, NJ 07940, USA. ademain@drew.edu
Newcomb
Michael
M
Wu
J H David
JH
D001426:Bacterial Proteins / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D002480:Cellulase / Q000378:metabolism*; D003013:Clostridium / Q000166:cytology / Q000201:enzymology; D048013:Acetivibrio thermocellus / Q000166:cytology / Q000201:enzymology*; D018920:Coculture Techniques; D004734:Energy Metabolism; D000431:Ethanol / Q000494:pharmacology*
D001426:Bacterial Proteins; D000431:Ethanol; D002244:Carbon; D002480:Cellulase