Abstract

To evaluate the fibrolytic potential of spent compost of champignon mushroom (Agaricus bisporus; SCAB) on forage degradation, liquids from spent compost were extracted and then evaluated in vitro. Firstly, SCAB was recovered at 50, 60 and 90 days post-harvest and enzyme activity was evaluated. Celluloses activity was highest at 60 days; xylanases activity was not affected by post-harvest stage; laccases activity increased as post-harvest stage increased. Secondly, liquid extracts of SCAB obtained at 60 days post-harvest were refrigerated, frozen, lyophilized and refrigerated plus benzoic acid, frozen plus benzoic acid, frozen plus glycerol or frozen plus benzoic acid-glycerol and then, the fibrolytic activity was evaluated. Fibrolytic activity was highest in SCAB frozen plus glycerol, lyophilization and frozen plus benzoic acid. Finally, effects of SCAB were evaluated on degradation of alfalfa hay, Taiwan grass, barley straw and spent compost ofA. bisporus. Dry matter soluble fraction of alfalfa and potential degradation of dry matter of Taiwan grass and barley straw were increased by SCAB. It was concluded that SCAB showed a high fibrolytic activity which would increase degradation of forages for ruminants.

Key words: Agaricus bisporus, degradation, fibrolytic enzymes, forages, ruminants.