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Title: Cellulose fermentation by a rumen anaerobic fungus in both the absence and the presence of rumen methanogens

Journal Article · · Appl. Environ. Microbiol.; (United States)
OSTI ID:6813631

The fermentation of cellulose by an ovine rumen anaerobic fungus in the absence and presence of rumen methanogens is described. In the monoculture, moles of product as a percentage of the moles of hexose fermented were: acetate, 72.7; carbon dioxide, 37.6; formate, 83.1; ethanol, 37.4; lactate, 67.0; and hydrogen 35.3. In the coculture, acetate was the major product (134.7%), and carbon dioxide increased (88.7%). Lactate and ethanol production decreased to 2.9 and 19% respectively, little formate was detected (1%), and hydrogen did not accumulate. Substantial amounts of methane were produced in the coculture (58.7%). Studies with (2-14C) acetate indicated that acetate was not a precursor of methane. The demonstration of cellulose fermentation by a fungus extends the range of known rumen organisms capable of participating in cellulose digestion and provides further support for a role of anaerobic fungi in rumen fiber digestion. The effect of the methanogens on the pattern of fermentation is interpreted as a shift in flow of electrons away from electron sink products to methane via hydrogen. The study provides a new example of intermicrobial hydrogen transfer and the first demonstration of hydrogen formation by a fungus. (Refs. 27).

Research Organization:
Applied Biochemistry Div., Dept. of Scientific and Industrial Research, Palmerston North, New Zealand
OSTI ID:
6813631
Journal Information:
Appl. Environ. Microbiol.; (United States), Vol. 42:6
Country of Publication:
United States
Language:
English