Chemical-free pretreatment of unwashed oil palm empty fruit bunch by using locally isolated fungus (Schizophyllum commune ENN1) for delignification

Abstract

Biological pretreatment of unwashed oil palm empty fruit bunch (OPEFB) by Schizopyllum commune ENN1 was carried out to obtain optimum conditions of delignification. Locally isolated fungus, S. commune ENN1, was grown on oily OPEFB and the biomass was simultaneously delignified. Hence, the incubation time (7d–28d), temperature (25°C–40°C), and amount of substrate (3g–9g) were investigated to improve the efficiency of lignin removal during the biological pretreatment. Maximum lignin peroxidase and manganese peroxidase were produced at each optimal parameter, and correlated with maximum lignin removal. A similar pattern of maximum cellulase was produced by S. commune ENN1 at optimal parameters with only minimal activity of around 5U/g (CMCase). A maximum lignin removal of 67.9% was achieved at optimum condition at a temperature of 30°C by using 5g of OPEFB after 14d of incubation time. The cellulose content was increased by 31.7% of the biologically pretreated OPEFB at optimum condition. These findings showed that S. commune ENN1 was feasible to remove the lignin and increase the cellulose content of unwashed OPEFB through biological pretreatment for enzymatic hydrolysis.