The Production of Fungal Mannanase, Cellulase and Xylanase Using Palm Kernel Meal as a Substrate

Extracellular enzymes including mannanase, cellulase and xylanase from Aspergillus wentii TISTR 3075, Aspergillus niger, Aspergillus oryzae, Trichoderma reesei TISTR 3080 and Penicillium sp. were investigated. The enzymes were produced in solid-state fermentation using palm kernel meal (PKM) as a substrate. All fungal strains produced mainly mannanase. A maximum activity of 24.9 U/g koji was observed in A. wentii TISTR 3075 with a specific activity of 1.5 U/mg protein. During PKM fermentation, there was also found low concomitantly of cellulase and xylanase activities with high mannanase activity in all strains. The degradation of non-starch polysaccharides (NSPs) in PKM by these fungal strains was indicated by the increased mannanase, cellulase and xylanase activities which correlated with the increase in reducing sugar content and pH profiles during PKM fermentation. PKM was shown to be more suitable for production of mannanase than cellulase and xylanase for all strains because of the high content of mannan as an inducer in PKM. Increases in enzyme yield might be obtained by optimizing the culture conditions.