title: Immobilization of yeast inulinase on chitosan beads for the hydrolysis of inulin in a batch system.
abstract: An extracellular inulinase was partially purified by ethanol precipitation and gel exclusion chromatography from a cell free extract of Kluyveromyces marxianus. Partially purified inulinase exhibited 420 IU/mg specific activity and it was immobilized on chitosan beads. Activity yield of immobilized inulinase was optimized with glutaraldehyde concentration (1-5%), glutaraldehyde treatment time (30-240min), enzyme coupling-time (2-16h) and enzyme loading (5-30 IU) as functions. Under the optimized conditions maximum yield 65.5% of immobilized inulinase was obtained. Maximum hydrolysis of inulin 84.5% and 78.2% was observed at 125rpm after 4h by immobilized and free enzyme, respectively. A retention-time of 4h and 5h was found optimal for the hydrolysis of inulin under agitation (125rpm) by free and immobilized enzyme, respectively. The recycling of the developed immobilized biocatalyst was carried out after 5h of inulin hydrolysis in a batch system. The developed immobilized biocatalyst was successfully used for the hydrolysis of inulin for 14 batches. This is the first report on the immobilization of yeast inulinase on chitosan beads for the hydrolysis of inulin in a batch system.
authors.affiliation: Carbohydrate and Protein Biotechnology Laboratory, Department of Biotechnology, Punjabi University, Patiala, 147 002, Punjab, India. Electronic address: rssingh11@lycos.com.
authors.forename: R S
authors.initials: RS
authors.lastname: Singh
authors.affiliation: Carbohydrate and Protein Biotechnology Laboratory, Department of Biotechnology, Punjabi University, Patiala, 147 002, Punjab, India.
authors.forename: R P
authors.initials: RP
authors.lastname: Singh
authors.affiliation: Chembiotech Laboratories, Advanced Science and Technology Institute, 5 The Croft, Buntsford Drive, Stoke Heath, Bromsgrove, Worcs B60 4JE, UK.
authors.forename: J F
authors.initials: JF
authors.lastname: Kennedy
mesh_terms: D055162:Biocatalysis; D048271:Chitosan / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000737:chemistry* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007444:Inulin / Q000378:metabolism*; D007700:Kinetics; D007716:Kluyveromyces / Q000201:enzymology*; D008863:Microspheres
chemical_list: D004800:Enzymes, Immobilized; D007444:Inulin; D048271:Chitosan; D006026:Glycoside Hydrolases; C023086:inulinase
keywords: Chitosan beads; Fructose; Immobilization; Inulin; Inulinase; Kluyveromyces marxianus