title: Enhanced production of bioethanol and ultrastructural characteristics of reused Saccharomyces cerevisiae immobilized calcium alginate beads.
abstract: Yeast immobilized on alginate beads produced a higher ethanol yield more rapidly than did free yeast cells under the same batch-fermentation conditions. The optimal fermentation conditions were 30°C, pH 5.0, and 10% initial glucose concentration with 2% sodium alginate beads. The fermentation time using reused alginate beads was 10-14 h, whereas fresh beads took 24h, and free cells took 36 h. All bead samples resulted in nearly a 100% ethanol yield, whereas the free cells resulted in an 88% yield. Transmission electron microscopy (TEM) showed that the shortened time and higher yield with the reused beads was due to a higher yeast population per bead as well as a higher porosity. The ultrastructure of calcium alginate beads and the alginate matrix structure known as the "egg-box" model were observed using TEM.
authors: Department of Wood Science and Landscape Architecture (BK21 Program), Chonnam National University, Gwangju 500-757, Republic of Korea.
authors: Kwang Ho
authors: KH
authors: Lee
authors: In Seong
authors: IS
authors: Choi
authors: Young-Gyu
authors: YG
authors: Kim
authors: Duck-Joo
authors: DJ
authors: Yang
authors: Hyeun-Jong
authors: HJ
authors: Bae
mesh_terms: D000464:Alginates / Q000648:ultrastructure*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D006863:Hydrogen-Ion Concentration; D046529:Microscopy, Electron, Transmission; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D013696:Temperature
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D000431:Ethanol; D020723:Glucuronic Acid; D005947:Glucose