Abstract
Cellulase and hemicellulase, both free and bound to cellulose, were produced in shake cultures of L. trabea and P. versicolor grown on ball-milled aspen (Populus tremuloides) or filter paper. Most of the enzyme was initially bound to cellulose plus mycelium and could not be readily dislodged, even by ultrasonic disintegration. Proportionally more enzyme could be obtained in the supernatant by reducing the cellulose concentration in the medium. No correlation was observed between the amount of growth and the amount of enzyme production. Rather, enzyme production was shown to be influenced by regulation of the growth rate through the use of cellulosic substrates of varying ease of accessibility and also when cultures were continuously supplied with glucose at a slow rate.