The effectiveness of bio-delignification empty fruit bunch of palm oil by Aspergillus fumigatus: Targeting for bio-hydrogen production

As the world's No. 1 producer of oil palm, Indonesia yields a huge amount of palm oil empty fruit bunch (EFB) as the biomass wastes. These EFB wastes are considered as a potential source of biofuel. Three fungal species isolated from different sources of indigenous Indonesian fungi (wood, bamboo, and oil palm empty fruit bunch) were evaluated for their capability to improve hydrolytic enzymes to biodegrade EFB and release sugars. The most potential fungus was obtained from EFB and identified as Aspergillus fumigatus. Bio-delignification using A. fumigatus was very effective for semisolid- or solid-fermentation in the short duration of 7 days. The lignin was reduced up to 4.19 % without significant reduction of cellulose and hemicellulose contents. This duration was considered optimal to maintain a high amount of cellulose-hemi cellulose in EFB and to allow the partial degradation of the lignin for accessible cellulase. The effectiveness of the cellulase to access EFB was examined by enzymatic saccharification. The result showed that the reducing sugar of enzymatic saccharification on biodelignified EFB reached 6.64 g/L, which was 40% higher than that for un-biodelignified EFB. The optimal EFB saccharification was 27 FPU/g EFB with the highest reducing sugar of 8.60 g/L. Furthermore, the resulting sugar, as an intermediate product, can be used to produce hydrogen by E. aerogenes.