title: Cagelike mesoporous silica encapsulated with microcapsules for immobilized laccase and 2, 4-DCP degradation.
abstract: In this study, cage-like mesoporous silica was used as the carrier to immobilize laccase by a physical approach, followed by encapsulating with chitosan/alginate microcapsule membranes to form microcapsules of immobilized laccase based on layer-by-layer technology. The relationship between laccase activity recovery/leakage rate and the coating thickness was simultaneously investigated. Because the microcapsule layers have a substantial network of pores, they act as semipermeable membranes, while the laccase immobilized inside the microcapsules acts as a processing plant for degradation of 2,4-dichlorophenol. The microcapsules of immobilized laccase were able to degrade 2,4-dichlorophenol within a wide range of 2,4-dichlorophenol concentration, temperature and pH, with mean degradation rate around 62%. Under the optimal conditions, the thermal stability and reusability of immobilized laccase were shown to be improved significantly, as the removal rate and degradation rate remained over 40.2% and 33.8% respectively after 6cycles of operation. Using mass spectrometry (MS) and nuclear magnetic resonance (NMR), diisobutyl phthalate and dibutyl phthalate were identified as the products of 2,4-dichlorophenol degradation by the microcapsules of immobilized laccase and laccase immobilized by a physical approach, respectively, further demonstrating the degradation mechanism of 2,4-dichlorophenol by microcapsule-immobilized laccase.
authors.affiliation: School of Chemistry and Molecular Engineering, East China University of Science & Technology, Shanghai 200237, China.
authors.forename: Junya
authors.initials: J
authors.lastname: Yang
authors.affiliation: School of Chemistry and Molecular Engineering, East China University of Science & Technology, Shanghai 200237, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
authors.affiliation: School of Chemistry and Molecular Engineering, East China University of Science & Technology, Shanghai 200237, China. Electronic address: yxyang@ecust.edu.cn.
authors.forename: Yuxiang
authors.initials: Y
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
authors.forename: Hongming
authors.initials: H
authors.lastname: Yuan
authors.affiliation: Analysis Test Center, Yangzhou University, Yangzhou 225009, China.
authors.forename: Xiangnong
authors.initials: X
authors.lastname: Liu
mesh_terms: D002733:Chlorophenols / Q000378:metabolism*; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism*; D042845:Laccase / Q000737:chemistry* / Q000378:metabolism*; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D002733:Chlorophenols; D004800:Enzymes, Immobilized; D012822:Silicon Dioxide; D042845:Laccase; C004762:2,4-dichlorophenol
keywords: 2,4-Dichlorophenol; Degradation efficiency; Degradation mechanism; Laccase-cMSS; Reusability; mLbL-laccase