Preparation and optimization of cellulase cocktail to improve the bioethanol process

Abstract

ABSTRACTThe cellulase component ratio affects the bioethanol yield in the bioethanol process. A method to increase the enzymatic degradation efficiency of cellulose is by preparing a cocktail of involved enzymes. The aim of this study is cocktail preparation and optimization which will reduce the cost of bioethanol process hydrolysis. Moreover, best enzyme composition and ratio depends on the substrate and type of the performed pretreatment. In the present study, response surface methodology (RSM) was used to optimize the ratio of three cellulase involved enzymes, including Exo-1,4-β-D-glucanases II (CBHII), Endo-1,4-β-D-glucanases II (EGII) and 1,4-β-D-glucosidases I (BGI), for degradation of pretreated bagasse. A cellulase activity based on the glycan residue formation was monitored using high performance Liquid Chromatography-Mass Spectrometry (LC-ESI/MS). In addition to cocktail production, the influential parameters affecting the process were studied and the best rate of enzymatic cocktail was adjusted to 1:5:1 (mg/g bagasse) EGII, CBHII and BGLI, respectively. Results revealed that the highest rates of glucose production were 20.5 and 41.4 mg/g within 24 and 48 h, respectively.