Xylan-digesting Bacteria from the Rumen of Sheep Fed Maize Straw Diets

Abstract

Summary: Representatives of a large number of bacterial isolates that produced clearings in xylan agar medium in an earlier study were characterized in greater detail. Butyrivibrios and ruminococci predominated. Three different biotypes of Butyrivibrio fibrisolvens, all non-cellulolytic, were identified on the basis of net acetate production or uptake, or the production of propionate. The only variable characteristic observed within the group of Ruminococcus albus isolates was the ability to solubilize cellulose. In contrast, all typical Ruminococcus flavefaciens isolates were cellulolytic. Other bacteria that occurred in smaller numbers belonged to the genera Eubacterium, Coprococcus, Fusobacterium, Bacteroides, Treponema and Clostridium.