[Hydrolysis of cellulose by fungi. II. Production of cellulases by Trichoderma harzianum by fermentation in liquid media].

Abstract

Microcristalline cellulose (cellulose Avicel, Merck) supported growth of Trichoderma harzianum and induced production of cellulases in liquid cultures. After 50 h growth, the total cellulasic activities present in both the supernatant and the mycelium were 3,000 IU/l of carboxymethyl cellulose, 400 IU/l of filter paper activity, and 4 IU/l of cotton activity corresponding to 1.7 g/l of proteins. Cellulase production could be increased by a preliminary treatment of cellulose, and pH regulation during growth. The influence of inoculum concentration was studied and an optimum of 3 x 10(7) conidia/g dry weight of substrate was demonstrated. Using a synthetic culture medium, a soluble factor of germination was demonstrated which could be leached out by 3 successive washings of conidia.