Abstract:

Cellulose degradation and fermentation by the ruminal cellulolytic microorganism. Ruminococcus flavefaciens strain 007, R. albus strain 7 and Neocallimastix frontalis strain MCH3 were studied in the absence and presence of acetogenic or sulfate-reducing ruminal bacteria. The presence of the H 2 -utilizing acetogens led to an increase in the cellulose breakdown by the two bacterial species and affected the kinetics of cellulose degradation by N. frontalis . The sulfate-reducing bacterium slightly increased cellulose degradation by R. albus , had no effect on cellulolysis by R. flavefaciens and inhibited the fungus N. frontalis . In the presence of the acetogens or sulfate-reducing bacteria there was a shift in the metabolism of the cellulolytic microorganisms towards greater production of acetate. Therefore, this study demonstrates that acetogens can interact with H 2 -producing cellulolytic microorganisms and that acetogenesis is a possible alternative to methanogenesis to eliminate H 2 from the ruminal ecosystem.

Keywords: rumen; acetogens

Language: English

Document Type: Miscellaneous

Affiliations: Laboratoire de Microbiologie, INRA, Centre de Recherches de Clermont-Ferrand-Theix, Saint-Genes-Champanelle, 63122, France: