title: Enhancement of immobilized lipase activity by design of polymer brushes on a hollow fiber membrane.
abstract: A polymer brush possessing aminoethanol (AE) functional groups for lipase immobilization was grafted onto a hollow fiber membrane by radiation-induced graft polymerization. Almost the AE groups-grafted polymer brushes unfold through positive charge repulsion between the AE groups, enabling multi-layer immobilization of lipase. The hydroxyl groups in AE can also retain water molecules around hydrophilic part of the lipase. In this study, we controlled the length and density of the polymer brushes consisting of the glycidyl methacrylate (GMA) by changing the concentration of GMA monomer during radiation-induced graft polymerization. Immobilized lipase showed the highest activity on the grafted membrane when 5 wt% of glycidyl methacrylate as monomer for the radiation-induced graft polymerization was used. Consequently high efficiency esterification (approximately 1600 mmol/h/g-membrane) was achieved in five-layer lipase on AE polymer brush than that in monolayer lipase on the polymer brush possessing only hydroxyl groups. Moreover, the polymer brush possessing AE functional groups for lipase immobilization maintained high activity on the reuse for several times.
authors.affiliation: Department of Chemical Science and Engineering, Ariake National College of Technology, 150 Higashihagio-Machi, Omuta, Fukuoka 836-8585, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Okobira
authors.affiliation: Department of Chemical Science and Engineering, Ariake National College of Technology, 150 Higashihagio-Machi, Omuta, Fukuoka 836-8585, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Matsuo
authors.affiliation: Department of Chemical Science and Engineering, Ariake National College of Technology, 150 Higashihagio-Machi, Omuta, Fukuoka 836-8585, Japan.
authors.forename: Hikaru
authors.initials: H
authors.lastname: Matsumoto
authors.affiliation: Department of Life and Environment Engineering, Faculty of Environmental Engineering, The University of Kitakyushu, 1-1 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0135, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Department of Life and Environment Engineering, Faculty of Environmental Engineering, The University of Kitakyushu, 1-1 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0135, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Kai
authors.affiliation: Department of Life and Environment Engineering, Faculty of Environmental Engineering, The University of Kitakyushu, 1-1 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0135, Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Minari
authors.affiliation: Kitakyushu National College of Technology, 5-20-1 Shii, Kokuraminami-ku, Kitakyushu, Fukuoka 802-0985, Japan.
authors.forename: Muneharu
authors.initials: M
authors.lastname: Goto
authors.affiliation: Department of Chemistry and Applied Chemistry, Faculty of Science and Engineering, Saga University, 1-Honjo, Saga 840-8502, Japan.
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Kawakita
authors.affiliation: Department of Life and Environment Engineering, Faculty of Environmental Engineering, The University of Kitakyushu, 1-1 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0135, Japan. Electronic address: uezu@kitakyu-u.ac.jp.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Uezu
mesh_terms: D055162:Biocatalysis; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D004852:Epoxy Compounds / Q000737:chemistry; D017743:Equipment Reuse; D004951:Esterification; D019856:Ethanolamine; D057927:Hydrophobic and Hydrophilic Interactions; D008049:Lipase / Q000737:chemistry / Q000378:metabolism*; D008567:Membranes, Artificial; D008689:Methacrylates / Q000737:chemistry; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D004852:Epoxy Compounds; D008567:Membranes, Artificial; D008689:Methacrylates; D011108:Polymers; D014867:Water; D019856:Ethanolamine; D008049:Lipase; C007870:glycidyl methacrylate
keywords: Biodiesel fuel; Esterification; Immobilized enzyme; Polymer brush; Radiation-induced graft polymerization; Rhizopus oryzae