Induction of Cellulase by Gentiobiose and Its Sulfur-Containing Analog in Penicillium purpurogenum.
Cellulase induction by beta-glucodisaccharides was investigated by using non-cellulase-induced mycelia of Penicillium purpurogenum P-26, a highly-cellulase-producing fungus. Gentiobiose induced significant amounts of cellulase compared with cellobiose when nojirimycin was added to the induction medium to inhibit extracellular beta-glucosidase activity. Thiogentiobiose (6-S-beta-d-glucopyranosyl-6-thio-d-glucose), a sulfur-containing analog of gentiobiose, was more effective for cellulase induction than gentiobiose even in the absence of nojirimycin. Thiogentiobiose appeared to be a gratuitous inducer since it was not metabolized during cellulase induction. Gentiobiose was formed from cellobiose by the intracellular beta-glucosidase of P. purpurogenum. These findings indicate that gentiobiose is an active inducer of cellulase for this fungus and may possibly be formed by intracellular beta-glucosidase from cellobiose.
Kurasawa
T
T
Department of Agricultural Biochemistry, Faculty of Agriculture, Hokkaido University, Sapporo 060, and Fermentation Research Institute, Agency of Industrial Science and Technology, Tsukuba, Ibaraki 305, Japan.
Yachi
M
M
Suto
M
M
Kamagata
Y
Y
Takao
S
S
Tomita
F
F