Prebleaching potential of xylanases from melanocarpus albomyces

摘要

The ascomycetous fungus Melanocarpus albomyces IIS68 produced xylanse and beta-xylosidase when grown on various substrates. Wheat straw resulted not only in the maximum xylanase production but also in the biosynthesis of the maximum (seven) xylanase isoenzymes, namely, Ia, Ib, Ic, IIa, IIb, IIc and IId. Out of seven isoenzymes the regulation of xylanase Ic seemed to be constitutive in nature. Three isoenzymes (Ia, Ib and Ic) having low molecular weights could be useful in pulp bleaching owing to chances of their greater access in the interior of the pulp. Two isoenzymes (IIa and IIc), on the basis of their alkaline pH optima, can also be used for prebleaching of the kraft pulps. Prelimianry studies on application potential of xylanolytic system of M. albomyces as pre-bleaching agent are reported.