Activity of the cellulase complex enzymes and xylanase in bacteria of the genus Ruminococcus

The activities of cellulases and xylanase were determined in 27 strains of the genus Ruminococcus. The cellulase complex of ruminococci was found to i nclude endo-1,4-beta-glucanase, cellobiohydrolase, and beta-glucosidase; th e activities of these enzymes significantly increased when purified cellulo se (filter paper) in the medium was replaced with natural cellulose (wheat straw). The activities of endo-l,4-beta-glucanase and cellobiohydrolase in high- and medium-activity strains were similar, while in low-activity strai ns hydrolyzing cellulose within 84 h or more, these activities were signifi cantly lower (p < 0.05). The activity of beta-glucosidase in high-, medium- , and low-activity ruminococcal cultures was virtually the same. The bacter ia secreted cellulases into the culture liquid, but about 60% of endo-l,4-b eta-glucanase, 55% of cellobiohydrolase, and 48% of beta-glucosidase were f ound in the cellular extract. Ruminococcal xylanase proved to be a constitu tive-inducible enzyme; its activity did not differ significantly in strains hydrolyzing cellulose quickly (48 h) and slowly (84 h); half of the activi ty was found in the culture liquid.