Hemicellulose‐degrading Enzymes Synthesized by Rumen Bacteria

Abstract

Over 100 bacterial cultures isolated from ovine rumen contents by enrichment techniques in polysaccharide‐containing media were examined for the ability to degrade plant cell wall structural polysaccharides. Approximately two‐thirds of the isolates retained were Gram negative and amongst the coccoid isolates diplococci predominated. Many of the rods examined were piliated and/or flagellated. Thirty of the more active xylan‐ and arabinan‐degrading isolates were examined for both the production and activity of the principal polysaccharidase and glycosidase enzymes associated with plant cell wall polysaccharide hydrolysis, following culture in a hemicellulose containing growth medium. The wide range of glycosidase activities detected in these hemicellulolytic isolates was evidence for their rôle in the breakdown of dietary polysaccharides in the rumen.