We studied the hydrolysis of carboxymethylcellulose at 50degreesC and pH 4.9 with a commercial preparation of cellulase (Celluclast) supplemented with a commercial beta-1,4-glucosidase product (Novozym). The initial concentration of carboxymethylcellulose was varied between 2 and 12.5 kg m(-3) for assays with Celluclast and two Novozym/Celluclast ratios (0.5 and 1). We determined the conversion to glucose and the overall conversion in terms of glucose equivalent. Conversion to glucose turned out to be directly proportional to the product of experimental time multiplied by the concentration of Celluclast and the constant of proportionality increased concomitantly with the concentration of Novozym. Overall conversion remained unaffected by the concentration of Novozym.