Ethanol production by thermophilic bacteria: fermentation of cellulosic substrates by cocultures of Clostridium thermocellum and Clostridium thermohydrosulfuricum

Journal Article · Mon Jun 01 00:00:00 EDT 1981 · Appl. Environ. Microbiol.; (United States)

OSTI ID:6298673

Ng, T K; Ben-Bassat, A; Zeikus, J G

The fermentation of various saccharides derived from cellulosic biomass to ethanol was examined in mono- and cocultures of Clostridium thermocellum strain LQRI and C. thermohydrosulfuricum strain 39E. C. thermohydrosulfuricum fermented glucose, cellobiose, and xylose, but not cellulose or xylan, and yielded ethanol/acetate ratios of >7.0 C. thermocellum fermented a variety of cellulosic substrates, glucose, and cellobiose, but not xylan or xylose, and yielded ethanol/acetate ratios of approx. 1.0. A stable coculture that contained nearly equal numbers of C. thermocellum and C. thermohydrosulfuricum was established that fermented a variety of cellulosic substrates, and the ethanol yield observed was twofold higher than in C. thermocellum monoculture fermentations. The metabolic basis for the enhanced fermentation effectiveness of the coculture on Solka Floc cellulose included: the ability of C. thermocellum cellulase to hydrolyze ..cap alpha..-cellulose and hemicellulose; the enhanced utilization of mono- and disaccharides by C. thermohydrosulfuricum; increased cellulose consumption; threefold increase in the ethanol production rate; and twofold decrease in the acetate production rate.

• Research Organization: Univ. of Wisconsin, Madison
• OSTI ID: 6298673
• Journal Information: Appl. Environ. Microbiol.; (United States), Vol. 41:6
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CELLOBIOSE
FERMENTATION
CELLULOSE
GLUCOSE
XYLANS
XYLOSE
CLOSTRIDIUM
ETHANOL
ALCOHOLS
ALDEHYDES
BACTERIA
BIOCONVERSION
CARBOHYDRATES
DISACCHARIDES
HEMICELLULOSE
HEXOSES
HYDROXY COMPOUNDS
MICROORGANISMS
MONOSACCHARIDES
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
PENTOSES
POLYSACCHARIDES
SACCHARIDES
550700* - Microbiology
550200 - Biochemistry