ISOLATION AND CHARACTERIZATION OF SELENOMONAS-RUMINANTIUM STRAINS CAPABLE OF 2-DEOXYRIBOSE UTILIZATION

Microbes from ruminal contents of cattle were selectively enriched by using 2-deoxyribose (2DR) as a substrate for growth. Bacterial isolate s growing on 2DR were gram-negative, curved, motile rods. The isolates grew on a broad range of substrates, including deoxyribose, glucose, ribose, mannitol, and lactate as well as ribonucleosides and deoxyribo nucleosides. The strains also grew on rhamnose (6-deoxymannose) but no t DNA. Organic acids produced from growth on hexoses and pentoses incl uded acetate, propionate, lactate, and succinate. The isolates were id entified as Selenomonas ruminantium subsp. lactilytica on the basis of morphology, substrate specificity, and other biochemical characterist ics. Several characterized species of ruminal bacteria were also scree ned for growth on 2DR, with only one strain (S. ruminantium PC-18) fou nd able to grow on 2DR. Ethanol was produced by 2DR when strains were grown on ribose or 2DR.