Abstract
Three basidiomycetes, Pleurotus salmoneostramineus, Pleurotus cystidiosus, Auricularia polytricha, were in- oculated at 25℃ on a bagasse-basal media for 30, 60, 90, and 120 days without fruiting and investigated on effects on chemical structure and rumen degradability of bagasse. The basidiomycetes degraded more hemicelluloses and lignin in the media than celluloses;the most powerful species, Auricularia polytricha, degraded hemicellulose and lignin up to 31% and 40.4% , respectively. Those were also accompanied with extensive breakdown of cross- linkages between lignin and carbohydrates, as estimated by lower concentration of ferulate ethers after the inoculation. In contrast with lower degradation of celluloses by basidiomycetes, rumen degradability of celluloses in the basidiomycetes-inoculated bagasse was improved by about 250-400% of that of the original bagasse, in good agreement with microscopic observation of exposed cellulose microfibril around the hyphae. Lesser increased degradability of hemicelluloses in the rumen appeared to be associated with selective degradation of arabinose and xylose residues but not of uronic acids and glucose and mannose residues by the basidiomycetes. Changes in particle sizes, moisture retention, and cellulose crystalline index were also discussed in relation to the baggase degradability.
