CELLULOSE DEGRADATION BY 2 RUMEN ANAEROBIC FUNGI IN MONOCULTURE OR IN COCULTURE WITH RUMEN BACTERIA

Cellulose (Whatman filter paper No. 1) degradation and fermentation by the rumen fungi, Piromonas communis strain FL and Sphaeromonas communis strain FG10, have been investigated. The amount of cellulose degraded by pure fungal cultures and by an association of fungi with either the fermentative bacterium Selenomonas ruminantium strain WPL or the methanogen Methanobrevibacter ruminantium (D.S.M. 1093) was measured. In pure culture, Piromonas communis FL degraded cellulose more efficiently than Sphaeromonas communis. The association of Piromonas communis with Selenomonas ruminantium depressed the cellulolytic activity of the fungus. By contrast, the co-culture Sphaeromonas communis-Selenomonas ruminantium was more efficient in the breakdown of paper than was the monoculture of Sphaeromonas communis. The The cellulolytic activity of Sphaeromonas communis was increased by the presence of Methanobrevibacter ruminantium. In coculture with Piromonas communis, the bacterium had a limited effect, probably because the fungal strain used was itself able to degrade cellulose very rapidly. The metabolism of Piromonas communis and Sphaeromonas communis was shifted towards acetate production with a concomitant decrease in lactate and ethanol production. Assay of protein indicated that the fungal biomass increased in the presence of the methanogen.