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In the present study, a fungal strain was isolated from mushroom waste dump-site and was described based on the morphological and molecular characteristics. The crude enzymatic extract was prepared by fermenting pineapple peels using the newly isolated fungal strain under solid-state condition. The enzymatic saccharification conditions of mushroom were optimized using the central composite design based on the response surface methodology. The isolate had black colony color, conidial head biseriate and small conidia which are synonymous with Aspergillus niger. The phylogenetic analysis using the rDNA ITS sequencing further revealed that the isolate was identical (≥99%) to A. niger. The crude extract displayed CMCase, Fpase and xylanase activities of 20.73U/mL, 34.57U/mL and 118.03U/mL respectively. The saccharification using the crude extract at optimal conditions of pH 6.5, temperature 50oC, enzyme loading of 5% (v/v) and time of 12h achieved maximum glucose yield of 1.639 mg mL-1 which is 1.1 folds higher than the predicted value. This study demonstrated the potential use of crude enzymatic extract from the newly isolated A. niger as a viable and efficient low-cost approach to mushroom processing using enzymes.

Mushrooms are a rich source of high value compounds. Efficient enzymatic degradation of mushroom cell-wall matrix is therefore critical in the recovery of cellular components in high yields. In the present study, the effect of reaction variables on mushroom saccharification using crude enzymatic extract was evaluated and optimized using the central composite design based on the response surface methodology. The crude extract displayed CMCase, Fpase and xylanase activities of 1.23Umg− 1 protein, 0.95Umg− 1 protein and 1.52 Umg− 1 protein. The model was validated by the analysis of variance with a coefficient of determination of 0.866 and F test value of 7.39, making the model valid at the 95 % confidence limit. The model achieved glucose yield of 1.490mg/mL at pH 6.5, temperature 50oC, enzyme load of 5% (v/v) and reaction time of 12h. The experiment using optimal model conditions yielded 1.582 mg/mL glucose which is 1.1 folds higher than the predicted model value. This study demonstrated potential of crude extract from solid-state fermentation of low-cost pineapple peels in mushroom processing.