Cellulase activities were detected in a culture supernatant concentrate (designated EX) and a cell extract (designated IN) of Acetobacter xylinum subsp. sucrofermentans BPR2001. IN and EX each hydrolyzed carboxymethylcellulose (CMC) strongly, but neither hydrolyzed bacterial cellulose (BC), Avicel or cellobiose. However, they did decrease the degree of polymerization of BC. By contrast, IN hydrolyzed cellotriose (G3). From the results of TLC assays and pH stability tests, it is suggested that this organism produces not only CMCase but also another cellulase, G3ase.