title: Optimization of cellulase mixture for efficient hydrolysis of steam-exploded corn stover by statistically designed experiments.
abstract: To improve the enzymatic hydrolytic efficiency and reduce production cost, a statistically designed experimental approach was used to optimize the composition of cellulase mixture so as to maximize the amount of glucose produced from steam-exploded corn stover (SECS). Using seven purified enzymes (cellobiohydrolases, Cel7A, Cel6A, Cel6B; endoglucanases, Cel7B, Cel12A, Cel61A; and beta-glucosidase) from Trichoderma viride T 100-14 mutant strain, a multi-enzyme mixture was constituted after screening and optimization. The final optimal composition (mol%) of the multi-enzyme mixture was Cel7A (19.8%), Cel6A (37.5%), Cel6B (4.7%), Cel7B (17.7%), Cel12A (15.2%), Cel61A (2.3%) and beta-glucosidase (2.8%). The subsequent verification experiments followed by glucose assay together with scanning electron microscopy (SEM) observation confirmed the validity of the models. The multi-enzyme mixture displayed a high performance in converting the cellulosic substrate (SECS). The amount of glucose produced (15.5mg/ml) was 2.1 times as that of the crude cellulase preparation. The results indicated that the optimized cellulase mixture is an available and efficient paradigm for the hydrolysis of lignocellulosic substrate. The enhanced cellulolytic activity displayed by the constructed cellulase mixture could be used as an effective tool for producing bioethanol efficiently from cellulose.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, National Engineering Research Center for Biotechnology (Shanghai), East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, PR China.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhou
authors.forename: Yong-Hong
authors.initials: YH
authors.lastname: Wang
authors.forename: Ju
authors.initials: J
authors.lastname: Chu
authors.forename: Ling-Zhi
authors.initials: LZ
authors.lastname: Luo
authors.forename: Ying-Ping
authors.initials: YP
authors.lastname: Zhuang
authors.forename: Si-Liang
authors.initials: SL
authors.lastname: Zhang
mesh_terms: D002480:Cellulase / Q000737:chemistry*; D020650:Combinatorial Chemistry Techniques / Q000379:methods*; D045424:Complex Mixtures / Q000737:chemistry; D003198:Computer Simulation; D004789:Enzyme Activation; D005947:Glucose / Q000138:chemical synthesis*; D006868:Hydrolysis; D008956:Models, Chemical; D035261:Plant Components, Aerial / Q000737:chemistry*; D011786:Quality Control; D012107:Research Design; D013227:Steam; D003313:Zea mays / Q000737:chemistry*
chemical_list: D045424:Complex Mixtures; D013227:Steam; D002480:Cellulase; D005947:Glucose