Physiological Studies on Phymatotrichum Omnivorum XI. Cellulolytic Enzymes

SUMMARY

Cell-free culture filtrates of Phymatotrichum fimicola, P. fungicola and P. omnivorum, grown on different carbon sources, were assayed for extracellular cellulases. In all three, cellulase synthesis was higher in carboxymethylcellulose media than in cellobiose media. Phymatotrichum omnivorum could not degrade filter paper whereas the other two fungi could. Most likely, P. omnivorum synthesized the C_x but not the C₁ enzyme, and P. fimicola and P. fungicola synthesized both enzymes inductively. This concords with our earlier finding that P. fimicola and P. fungicola were physiologically the same but morphologically different. In contrast, P. omnivorum differed from the other two species both morphologically and physiologically. All other properties of the cellulase system of the species of Phymatotrichum are identical to those of other mesophilic fungi.