Diversity of Subgroup of Fibrobacter succinogenes in the Rumen and Feces of Cattle and Sheep

Fibrobacter succinogenes is the most important microbe in terms of fiber degradation in the rumen of ruminants and is known to be a phylogenetically diverse group of species. This study aimed to examine the ecology and diversity of F. succinogenes in the rumen and hindgut of cattle and sheep using a species-specific primer set. Using this technique, six clone libraries were constructed, and the cloned sequences were analyzed. FS I was dominated by cattle rumen fluid (CRF), cattle rumen mat (CRM), sheep rumen fluid (SRF), and sheep rumen mat (SRM). FS II was dominated by cattle feces (CFE). FS III was dominated by sheep feces (SFE). FS III and IV were commonly detected in both CFE and SFE. Horse and capybara group was detected in SFE. Abundance of F. succinogenes was determined by species specific real-time PCR assay. The abundance in the rumen mat was significantly higher than in the rumen fluid and feces in cattle (p < 0.01). In conclusion, the composition of the Fibrobacter group in the rumen was different from that in the feces, indicating that the composition in the feces does not directly reflect the composition of the rumen.