Cellulolytic activity of the rumen bacterium Bacteroides succinogenes

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Abstract
Bacteroides succinogenes S-85 grows readily in media containing 0.2% (w/v) filter paper cellulose or microcrystalline ellulose as the carbohydrate source. During growth, the cells appear to adhere to the cellulose. Cell-free culture supermates and ell extracts from cellulose-grown cultures had very low hydrolytic activity against either filter paper or crystalline cellulose Avicel) as substrate, although H3PO4-swollen cellulose, carboxymethylcellulose, and cellobiose were readily hydrolyzed. Cells rown on either cellobiose or glucose exhibited cell-bound carboxymethylcellulase (CMCase) and cellobiase activities. Cultures rown on cellulose had seven to eight times more CMCase activity than either cellobiose- or glucose-grown cultures. Seventy ercent of the CMCase activity was present in the supernate, of which 50–60% was associated with sedimentable membranous ragments. The cellobiase, which was largely cell associated, appeared to be constitutive, and the only product detected on nzymic hydrolysis of cellobiose was glucose. The cellobiase activity was strongly inhibited by 0.02 M tris(hydroxymethyl)-minomethane (Tris), pH 7.1, but this was partially relieved by phosphate ions. These data indicate that B. succinogenes -85 contains high endo-β-1,4-glucanase and β-1,4-glucosidase-like activities.