Tannin-tolerant ruminal bacteria from East African ruminants

Three strains of tannin-tolerant rumen bacteria were isolated from enrichme nt cultures of rumen microflora of sheep, goat, and antelope and establishe d in medium containing high concentrations of crude tannin extract or tanni c acid. These three strains (EAT2, ES3, and EG19), characterized as Selenom onas species, were curved rods, obligately anaerobic, Gram negative, highly motile, and grew in media containing 50 g of tannin extract/L and 50-70 g of tannic acid/L. Strain EAT2 was able to hydrolyze gallic acid, while stra ins ES3 and EG19 hydrolyzed tannic acid but not gallic acid. All isolates w ere able to grow in media containing up to 8 g of condensed tannins/L. Grow th was very slow when soluble carbohydrate was not added to the medium.