Induction of xylanase and cellulase in Schizophyllum commune

Various mono-, oligo-, and polysaccharides were screened for their ability to induce the synthesis of xylanase and cellulase (endoglucanase) activity in the basidiomycete Schizophyllum commune. Constitutive synthesis of low activities was observed on easily metabolizable compounds or even in the absence of an added inducer. Formation of both xylanase and cellulase was induced by cellulose and cellulose-rich substrates, of which bacterial cellulose was by far the best inducer, as well as by the disaccharide cellobiose. Furthermore, compounds structurally related to the latter, including sophorose, lactose, and 4-O-beta-galactopyranosyl-D-mannopyranose, which was identified as a new inducer of xylanase and cellulase, provoked the synthesis of both enzymes significantly. Xylan isolated from birchwood, xylose, and beta-methyl-D-xyloside, a structural analogue of xylobiose, only resulted in the constitutive enzyme levels formed. These results indicate that the synthesis of xylanase and cellulase is likely to be under common regulatory control in S. commune. Two of the compounds found to provoke production of xylanase, lactose and cellulose, were used as substrates for laboratory fermentations.