B.fibrisolvens is located in the rumen of ruminant animals, where it contributes to the animal's digestion of plant material by hydrolyzing hemicellulose with its xylanases. Endohydrolysis of (1->4)-beta-D-xylosidic linkages in xylans. Glycan degradation; xylan degradation. Belongs to the glycosyl hydrolase 10 (cellulase F) family.