title: Immobilization of Piromyces rhizinflata β-glucanase on poly(dimethylsiloxane) and Si wafer and prediction of optimum reaction for enzyme activity.
abstract: EglA, a β-1,4-glucanase isolated from the ruminal fungus Piromyces rhizinflata, shows promise in a wide range of industrial applications because of its broad substrate specificity. In this study, EglA was immobilized on different supporting materials including poly(dimethylsiloxane) (PDMS), Si wafer, textured Si wafer, and indium tin oxide-coated (ITO-coated) glass. The binding abilities of PDMS and Si wafer toward EglA were significantly higher than those of the other supporting materials. The optimized temperature and pH conditions for EglA immobilized on PDMS and on Si wafer were further determined by a response surface methodology (RSM) combined with a central composite design (CCD). The results indicated that the optimum pH and temperature values as well as the specific β-glucanase activity of EglA on PDMS were higher than those of free-form EglA. In addition, EglA immobilized on PDMS could be reused up to six times with detectable enzyme activity, while the enzyme activity of Eg1A on Si wafer was undetectable after three cycles of enzyme reaction. The results demonstrate that PDMS is an attractive supporting material for EglA immobilization and could be developed into an enzyme chip or enzyme tube for potential industrial applications.
authors.affiliation: a Institute of Biotechnology , National Taiwan University , Taipei , Taiwan.
authors.forename: Chih-Wen
authors.initials: CW
authors.lastname: Tseng
authors.forename: Dan-Ju
authors.initials: DJ
authors.lastname: Yeh
authors.forename: Fang-Tzu
authors.initials: FT
authors.lastname: Chuang
authors.forename: Si-Chen
authors.initials: SC
authors.lastname: Lee
authors.forename: Je-Ruei
authors.initials: JR
authors.lastname: Liu
mesh_terms: D002480:Cellulase / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008962:Models, Theoretical; D020089:Piromyces / Q000201:enzymology*; D012044:Regression Analysis; D012825:Silicon / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature
chemical_list: D004129:Dimethylpolysiloxanes; D004800:Enzymes, Immobilized; C013830:baysilon; D002480:Cellulase; D012825:Silicon
keywords: Si wafer; central composite design; immobilization; poly(dimethylsiloxane); response surface methodology; β-1,4-glucanase