The cellulase of Trichoderma viride. Separation of the components involved in the solubilization of cotton.

1. Culture filtrates from Trichoderma viride have been fractionated by gel filtration on Sephadex G-75 followed by ion-exchange chromatography on DEAE- and SE-Sephadex. 2. The components essential for attack on cotton are a carboxymethylcellulase, a cellobiase and a third (C(1)) component which has no action on CM-cellulose, cellobiose or cotton. 3. These components, which together can completely convert cotton into water-soluble products, lose this ability when separated and regain it quantitatively when recombined in their original proportions.