CELLULOLYTIC ACTIVITIES OF BOTRYODIPLODIA THEOBROMAE PAT

Botryodiplodia theobromae Pat., a 'stain' fungus isolated from stained and decaying wood of Bombax buonopozense P. Beauv., attacked isolated blocks of Bombax wood. In these it perforated the cell walls and formed elongated cavities with pointed ends, usually in chains, in the secondary wall. The fungus attacked cellulose in a similar manner to soft rot fungi. It used starch and other saccharides present in the wood of Bombax buonopozense as initial substrates before degrading the cellulose and hemicellulose components of the wood. It did not degrade the lignin component of the wood.Cellulase, β-glucosidase, and amylase activities were detected in culture filtrates of Botryodiplodia theobromae. Cellulase synthesis was delayed when the wood powder in the medium contained starch and saccharides. Amylase, too, behaved like an inducible enzyme and disappeared from the cultures on exhaustion of starch.Electron microscopy showed that cellulose extracted from the wood of Bombax buonopozense was fragmented into small particles on treatment with the culture filtrates of Botryodiplodia theobromae. Cellobiose, glucose, and another saccharide, probably cellotriose, were identified as the products of enzymatic hydrolysis of cellulose.These results are discussed in relation to the attack and degradation of the wood of Bombax buonopozense by Botryodiplodia theobromae in nature. © 1969 OXFORD UNIVERSITY PRESS.