Fundamentals of Dark Hydrogen Fermentations: Multiple Pathways and Enzymes
Pp. 94-111 (18)
Patrick C. Hallenbeck
Biohydrogen production through dark fermentation could be a promising route to the
generation of a renewable fuel source. Dark fermentation is attractive since its deployment would
probably be based on known reactor technology, and, in a first application, could use various
carbohydrate rich waste streams, followed by lignocellulosics, a vast largely untapped resource. A
thorough understanding of the enzymes and pathways is involved would help develop strategies,
especially metabolic engineering, for improving rates and yields of hydrogen production. Here, the
various hydrogenases and their active sites and biochemistry are discussed followed by an examination
of known hydrogen producing pathways.
Hydrogen fermentation, [FeFe] hydrogenase, [NiFe] hydrogenase, Clostridium, Escherchia
coli, mixed acid fermentation, syntrophic metabolism, carbohydrate degradation, ethanol-acetate
cofermentation, redox balance.
Département de Microbiologie et Immunologie, Université de Montréal, Canada