title: Covalent Immobilization and Characterization of a Novel Pullulanase from Fontibacillus sp. Strain DSHK 107 onto Florisil® and Nano-silica for Pullulan Hydrolysis.
abstract: A novel pullulanase partially purified from Fontibacillus sp. was covalently immobilized on Florisil® and nano-silica through both glutaraldehyde and (3-glycidyloxypropyl)trimethoxysilane spacer arms. The pullulanase immobilized on Florisil® and nano-silica through glutaraldehyde spacer arm showed 85 and 190 % activity of its free form, respectively, whereas no activity was observed when it was immobilized on the same supports through (3-glycidyloxypropyl)trimethoxysilane spacer arm. The maximum working pHs of both the immobilized pullulanases on Florisil® and nano-silica through glutaraldehyde spacer arm were determined as 5.0; however, the maximum working pH of the free pullulanase was pH 6.0. The maximum temperatures of all the pullulanase preparations were determined as 35 °C. The apparent K m values were 1.49, 1.54, and 0.59 mg/mL pullunan, respectively, for the free and immobilized pullulanases on Florisil® and nano-silica. The corresponding apparent V max values were 0.59, 1.53, and 1.57 U mg prot.(-1) min.(-1). Thermal stability of pullulanases immobilized on Florisil® and nano-silica was enhanced 6.5- and 15.6-folds, respectively at 35 °C and 6.6- and 16.0-folds, respectively, at 50 °C. The pullulanases immobilized on Florisil® and nano-silica protected 71 and 90 % of their initial activities after 10 reuses.
authors.affiliation: Vocational School of Imamoglu, University of Cukurova, Adana, Turkey. dalagoz@cu.edu.tr.
authors.forename: Dilek
authors.initials: D
authors.lastname: Alagöz
authors.affiliation: Vocational School of Ceyhan, University of Cukurova, Adana, Turkey.
authors.forename: Deniz
authors.initials: D
authors.lastname: Yildirim
authors.affiliation: Faculty of Sciences and Letters, Department of Biology, University of Cukurova, Adana, Turkey.
authors.forename: Hatice Korkmaz
authors.initials: HK
authors.lastname: Güvenmez
authors.affiliation: Faculty of Sciences and Letters, Department of Biology, University of Cukurova, Adana, Turkey.
authors.forename: Damla
authors.initials: D
authors.lastname: Sihay
authors.affiliation: Faculty of Sciences and Letters, Department of Chemistry, University of Cukurova, Adana, Turkey.
authors.forename: S Seyhan
authors.initials: SS
authors.lastname: Tükel
mesh_terms: D056449:Bacillales / Q000201:enzymology; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D005936:Glucans / Q000737:chemistry* / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000737:chemistry* / Q000378:metabolism; D006868:Hydrolysis; D017633:Magnesium Silicates / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D005936:Glucans; D017633:Magnesium Silicates; C005013:Florisil; D012822:Silicon Dioxide; C009109:pullulan; D006026:Glycoside Hydrolases; C100181:pullulanase
keywords: Florisil®; Fontibacillus sp. pullulanase; Immobilization; Nano-silica; Pullulan