title: Identifying and overcoming the effect of mass transfer limitation on decreased yield in enzymatic hydrolysis of lignocellulose at high solid concentrations.
abstract: Cellulose conversion decreases significantly with increasing solid concentrations during enzymatic hydrolysis of insoluble lignocellulosic materials. Here, mass transfer limitation was identified as a significant determining factor of this decrease by studying the hydrolysis of delignified corncob residue in shake flask, the most used reaction vessel in bench scale. Two mass transfer efficiency-related factors, mixing speed and flask filling, were shown to correlate closely with cellulose conversion at solid loadings higher than 15% DM. The role of substrate characteristics in mass transfer performance was also significant, which was revealed by the saccharification of two corn stover substrates with different pretreatment methods at the same solid loading. Several approaches including premix, fed-batch operation, and particularly the use of horizontal rotating reactor were shown to be valid in facilitating cellulose conversion via improving mass transfer efficiency at solid concentrations higher than 15% DM.
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University, 250100, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Du
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University, 250100, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Cao
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University, 250100, China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University, 250100, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University, 250100, China.
authors.forename: Xuezhi
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University, 250100, China; National Glycoengineering Research Center, Shandong University, 250100, China. Electronic address: quyinbo@sdu.edu.cn.
authors.forename: Yinbo
authors.initials: Y
authors.lastname: Qu
mesh_terms: D001709:Biotechnology / Q000295:instrumentation / Q000379:methods*; D002482:Cellulose / Q000737:chemistry / Q000378:metabolism; D005949:Glucose Oxidase; D006868:Hydrolysis; D007784:Lactoperoxidase; D008031:Lignin / Q000737:chemistry* / Q000378:metabolism; D018520:Plant Shoots / Q000737:chemistry / Q000378:metabolism; D012212:Rheology; D014783:Viscosity; D003313:Zea mays / Q000737:chemistry* / Q000378:metabolism
chemical_list: C041744:enzymobeads; C036909:lignocellulose; D002482:Cellulose; D008031:Lignin; D005949:Glucose Oxidase; D007784:Lactoperoxidase
keywords: Cellulose conversion; High solid enzymatic hydrolysis; Lignocellulosic biomass; Mass transfer; Mixing