Saccharification of native and degraded cotton cellulose and commercial microcrystalline cellulose by Trichoderma viride cellobiohydrolase I.

The degree of polymerization of samples of acid degraded cotton cellulose has no appreciable influence on the saccharification by cellobiohydrolase I from Trichoderma viride. The increase in the number of cellulose molecule ends, achieved by a 30-fold decrease in molecular weight, does not produce the effect which could be expected for a pure end-wise mode of action of this exoglucanase. Microcrystalline celluloses saccharified by the same enzyme yield considerably more reducing sugars than cotton cellulose, either with a similar degree of polymerization or one of about 7000. It appears, therefore, that the difference in the susceptibility of the commercial substrates is not a consequence of their low degree of polymerization.