Influence of Carbon Source on Cellulase Activity of White-rot and Brown-rot Fungi

Three white-rot fungi, Polyporus versicolor, Ganoderma applanatum, and Peniopbora “G,” produce an adaptive cellulase complex that can degrade both soluble cellulose (Cx) and microcrystalline cellulose (C1), a highly ordered form of cellulose. Production of Cx and C1 by the white-rot fungi was repressed by simple sugars. Cellualase preparations from three brown-rot fungi, Poria monticola, Lentinus lepideus, and Lenzites trabea, exhibited only Cx activity; microcrystalline cellulose was not significantly degraded. Contrary to the cellulase (Cx) of the white-rot fungi, that of the brown-rot fungi apparently is constitutive, since activity was abundant in cultures with simple sugars or with non-cellulosic polysaccharides as the sole source of carbon. This work disclosed no differences between the celluase-inducing effects of hardwoods versus those of softwoods that might help explain the preference of white rotters for hardwoods and brown rotters for softwoods. Additional keywords: Polyporus versicolor, Ganoderma applanatum, Peniophora “G,” Poria monticola, Lentinus lepideus, Lenzites trabea, enzyme, decay.