A cellulase complex in culture filtrates of Penicillium citrinum

During growth in a liquid medium that contained a single soluble or an insoluble cellulosic carbon source Penicillium citrinum released a complex of cellulase enzymes into the medium. A temperature of 30 degrees C was best for cellulase production. Presence of carbon-containing compounds, particularly glucose, inhibited cellulase activity. The enzyme complex was separated by gel filtration followed by ion-exchange chromatography into 11 components, 4 of high molecular weight and 7 of low molecular weight. One of the components (Bb) had the character of C1 cellulase enzyme. When the components were combined they released more reducing sugars from cullulosic substrates than when they were used singly.