Abstract
Two species of basidiomycetes, Pleurotus salmoneostramineus and Aaricularia polytricha, were incubated in bagasse culture for 60 days without fruiting of the mushroom, and the effects on the improvement of rumen degradability of the cell walls of bagasse were then examined. Observations from scanning (SEM) and transmission (TEM) electron microscopy, and from ultraviolet microspectrometry, were also conducted from samples before and after treatment with basidiomycetes. Variations in the mode of bagasse cell wall degradation were then related to the enzymic activities of β-glucosidase, carboxymethyl cellulase, xylanase, and peroxidase in the two species of basidiomycetes incubated for 18 days in a submerged culture. Pleurotus salmoneostramineus, possessing higher fiber-degrading activities in cell-associated enzymes, was observed to penetrate and degrade the cell walls of bagasse. In contrast, Auricularia polytricha, possessing higher fiber- degrading activities of cell-free enzymes, was observed to degrade bagasse cell walls apart from the hypha of basidiomycetes, as shown in KMnO_4- and PATAg-stained TEM photographs. These data were discussed in relation to the effects on the decomposition and rumen degradability of cell wall constituents in bagasse.
