title: Non-ionic surfactants do not consistently improve the enzymatic hydrolysis of pure cellulose.
abstract: Non-ionic surfactants have been frequently reported to improve the enzymatic hydrolysis of pretreated lignocellulosic biomass and pure cellulose. However, how the hydrolysis condition, substrate structure and cellulase formulation affect the beneficial action of surfactants has not been well elucidated. In this work, it was found that the enzymatic hydrolysis of pure cellulose was not consistently improved by surfactants. Contrarily, high surfactant concentration, e.g. 5 g/L, which greatly improved the hydrolysis of dilute acid pretreated substrates, actually showed notable inhibition to pure cellulose conversion in the late phase of hydrolysis. Under an optimal hydrolysis condition, the improvement by surfactant was limited, but under harsh conditions surfactant indeed could enhance cellulose conversion. It was proposed that non-ionic surfactants could interact with substrates and cellulases to impact the adsorption behaviors of cellulases. Therefore, the beneficial action of surfactants on pure cellulose hydrolysis is influenced by hydrolysis condition, cellulose structural features and cellulase formulation.
authors.affiliation: Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Chen
authors.affiliation: College of Life Sciences/Engineering Research Center of Industrial Microbiology, Fujian Normal University, Fuzhou 350108, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Qi
authors.affiliation: Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China. Electronic address: zhaoxb@mail.tsinghua.edu.cn.
authors.forename: Xuebing
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Institute of Applied Chemistry, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Dehua
authors.initials: D
authors.lastname: Liu
mesh_terms: D000327:Adsorption; D044602:Cellulases / Q000737:chemistry / Q000378:metabolism*; D002482:Cellulose / Q000737:chemistry* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D011136:Polysorbates / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D011136:Polysorbates; D013501:Surface-Active Agents; D002482:Cellulose; D044602:Cellulases
keywords: Cellulase; Enzyme adsorption; Lignocellulose; Non-ionic surfactant; Pure cellulose