Pretreatment Effects on the Rice Bran Saccharification with Newly Identified Fungal Enzymatic Activities

In order to develop an efficient microbial source of cellulase enzyme system, cellulolytic fungal strain was newly isolated from traditional Korean nuruk samples in the present study. The crude enzyme extract of this fungal strain, avicelase, CMCase and β-glucosidase activities reached the maximal points of 6.73, 3.22, and 5.64 units/mL, respectively and was used for the subsequent enzymatic saccharification on pretreated deproteinised and lipid-extracted rice bran. This strain was identified as Penicillium sp. determined by cellular fatty acid composition analysis. Three different pretreatment conditions were evaluated on the deproteinised and lipid-extracted rice bran at 121°C/1.5 psi for 5 different residence times: one with 0.1 N sulfuric acid, another with 0.1 N sodium hydroxide, and the last with distilled water. The greatest enzymatic saccharification yield increased up to 75.2% from acid-catalyzed autoclaving pretreatment for 30 min. The acid-catalyzed autoclaving pretreatment enhanced the saccharifying ability of the newly isolated cellulolytic fungal strain on the deproteinised and lipid-extracted rice bran.