title: Immobilization of Saccharomyces cerevisiae on to modified carboxymethylcellulose for production of ethanol.
abstract: In this work, modified carboxymethylcellulose (CMC) was used as a new support material for production of ethanol. Crosslinked graft copolymers of CMC with N-vinyl-2-pyrrolidone (N-VP) were prepared in different grafting yields. The beads material was characterized by means of fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), scanning electron microscope (SEM) and swelling experiment. Saccharomyces cerevisiae was immobilized using entrapment method in the graft copolymers of carboxymethylcellulose-g-poly(N-vinyl-2-pyrrolidone) (CMC-g-PVP) for ethanol fermentation. The effects of grafting yield, initial glucose concentration and crosslinker concentration on the yield of ethanol process were investigated. Reusability of the immobilized yeasts was investigated and found that the materials can be used four times without losing their activity. Ethanol production increased to 59.3 g/L from 46.4 g/L when percentage of N-VP in the graft copolymer was increased. The highest ethanol productivity was found to be 1.75-2.25 g/L h. Fermentation time decreased with the decreasing of crosslinker concentration. The results suggest that the proposed method for immobilization of Saccharomyces cerevisiae has potential in industrial applications for ethanol process.
authors.affiliation: Department of Chemistry, Faculty of Science and Art, Kırıkkale University, Yahşihan, 71450, Kırıkkale, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Gökgöz
authors.forename: Mustafa
authors.initials: M
authors.lastname: Yiğitoğlu
mesh_terms: D019149:Bioreactors; D002152:Calorimetry, Differential Scanning; D002266:Carboxymethylcellulose Sodium / Q000737:chemistry* / Q000378:metabolism; D018914:Cells, Immobilized / Q000737:chemistry / Q000648:ultrastructure*; D000431:Ethanol / Q000138:chemical synthesis / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000737:chemistry / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D011108:Polymers / Q000737:chemistry / Q000378:metabolism; D011760:Pyrrolidinones / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism* / Q000648:ultrastructure; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D011108:Polymers; D011760:Pyrrolidinones; D000431:Ethanol; D005947:Glucose; D002266:Carboxymethylcellulose Sodium; C028537:2-pyrrolidone