Production of cellulases by Penicillium sp. in a solid-state fermentation of oil palm empty fruit bunch

To use oil palm empty fruit bunch (EFB) for cellulase production, a novel fungus was isolated from moistened EFB. This fungus was classified as Penicillium sp. by sequence analysis of the internal transcribing space and it was named Penicillium sp. GDX01. The Penicillium sp. strain secreted cellulases under solid-state fermentation of EFB. The fermentation conditions were optimized for maximal enzyme production. Of the different substrates tested, both EFB and rice straw gave the maximum production of filter paper activity (FPase). Five percent yeast extract and 40-50% initial moisture content were found to be optimal for enzyme production. In addition, the pretreatment of EFB with NaOH before fermentation inhibited the cellulase production of Penicillium sp. GDX01. Saccharification of pretreated EFB by cellulases from Penicillium sp. GDX01 resulted in a more than 80% release of glucose during a 72 h incubation, which is a better result than when using Celluclast 1.5L without the addition of β-glucosidase. Our results show that the cellulases produced by Penicillium sp. GDX01 are more efficient at the saccharification of EFB than Celluclast 1.5 L.   Key words: Cellulase, oil palm empty fruit bunch, solid-state fermentation, Penicillium.