REGULATION, PURIFICATION, AND PROPERTIES OF XYLANASE FROM CELLULOMONAS-FIMI

The production and regulation of xylanase was studied in Cellulomonas fimi. Activity was higher when the organism was grown on carboxymethylcellulose (CMC) and xylan than on other soluble substrates. Catabolite repression of xylanase activity occurred when glucose, cellobiose, and other readily metabolizable substrates were added during growth on CMC. Three xylanases, A, B, and C, were purified to homogeneity from the culture supernatant of Cellutomonas fimi by Q-Sepharose and Sepharose 6B chromatography. The molecular weights of the three enzyme components were 13,200, 22,000, and 150,000, respectively, and the K(m) values were 1.72, 1.68, and 1.25 mg ml-1, respectively.