A multienzyme complex, cellulosome, of the facultatively anaerobic bacterium, Paenibacillus curdlanolyticus B-6 was produced on microcrystalline cellulose (Avicel) under aerobic conditions. During growth on Avicel, the bacterial cells were found to be capable of adhesion to Avicel by scanning electron microscopic (SEM) analysis. The multienzyme complex of P. curdlanolyticus B-6 was isolated from the crude enzyme preparation by gel filtration chromatography on Sephacryl S-300 and affinity purification on cellulose. The isolated multienzyme complex was able to bind to both Avicel and insoluble xylan and consists of cellulolytic and xylanolytic enzymes such as avicelase, carboxymethyl cellulase (CMCase), cellobiohydrolase, beta-glucosidase, xylanase, beta-xylosidase and alpha-L-arabinofuranosidase. The molecular mass of the complex was estimated to be 1600 kDa. It composed of at least 12 proteins on SDS-PAGE and 10 CMCases and 11 xylanases on zymograms. The isolated multienzyme complex could degrade the raw lignocellulosic substances effectively. (C) 2009, The Society for Biotechnology, Japan. All rights reserved.