Ruminococcus

Abstract

Ru.min.o.coc'cus. L. adj. ruminalis of the rumen; Gr. n. kokkos a grain, berry; N.L. masc. n. Ruminococcus coccus of the rumen.

Firmicutes / “Clostridia” / Clostridiales / “Ruminococcaceae” / Ruminococcus

Cells are coccoid, usually 0.3–1.5 × 0.7–1.8 µm. Cells are in pairs and chains. A few are motile with 1–3 flagella. Gram-stain-positive cell-wall structure but many stain Gram-negative. Optimal temperature, 37–42°C. Chemo-organotrophic. Strictly anaerobic and require fermentable carbohydrates to grow. Fermentation of carbohydrate yields various proportions of acetate, formate, succinate, lactate, and ethanol. Amino acid and peptides are not fermented. Indole is not produced (Bryant, 1986). Isolated from rumen, large bowel, or cecum of many animals and humans. Some are isolated from human clinical specimens. Rumen fluid agar is effective to isolate and characterize strains (Holdeman et al., 1977). Some strains use cellulose on rumen fluid cellobiose agar plate (Holdeman et al., 1977) and require ammonia as a nitrogen source.

DNA G+C content (mol%): 39–47.

Type species: Ruminococcus flavefaciens Sijpesteijn 1948, 152^AL.