Isolation and partial characterization of Ruminococcus flavefaciens from the rumen of swamp buffalo

Abstract

The ability to utilize low-quality roughage of swamp buffalo has been reported, thus, rumen of swamp buffalo might be a suitable source for isolation of potent fibrolytic bacteria. A total of 165 gram-negative cocci fibrolytic bacteria were screened from rumen contents of 4 swamp buffalo. Six isolates were identified as Ruminococcus flavefaciens and phylogenetically grouped with type strain. Strain OS14 showed the highest fiber digestion alone or combination with non-fibrolytic bacteria and higher than type strain. DM digestibility of cellulose powder in co-culture of OS14 with all strains non-fibrolytic was increased. Moreover, co-culture of OS14 with S137 showed the highest fiber digestion and notably increased of acetate and propionate. These results indicated that possible cross-feeding between R. flavefaciens with non-fibrolytic bacteria could improve fiber digestion but the amount of improvement might be based on the combination of bacteria strains. The in vitro fermentation products and abundance in co-culture need to be quantified in further study