title: The effect of initial cell concentration on xylose fermentation by Pichia stipitis.
abstract: Xylose was fermented using Pichia stipitis CBS 6054 at different initial cell concentrations. A high initial cell concentration increased the rate of xylose utilization, ethanol formation, and the ethanol yield. The highest ethanol concentration of 41.0 g/L and a yield of 0.38 g/g was obtained using an initial cell concentration of 6.5 g/L. Even though more xylitol was produced when the initial cell concentrations were high, cell density had no effect on the final ethanol yield. A two-parameter mathematical model was used to predict the cell population dynamics at the different initial cell concentrations. The model parameters, a and b correlate with the initial cell concentrations used with an R(2) of 0.99.
authors.affiliation: Novozymes North America Inc., 77 Perry Chapel Church Road, Franklinton, NC 27525, USA. fkag@novozymes.com
authors.forename: Frank K
authors.initials: FK
authors.lastname: Agbogbo
authors.forename: Guillermo
authors.initials: G
authors.lastname: Coward-Kelly
authors.forename: Mads
authors.initials: M
authors.lastname: Torry-Smith
authors.forename: Kevin
authors.initials: K
authors.lastname: Wenger
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Jeffries
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D002452:Cell Count; D018929:Cell Culture Techniques / Q000379:methods*; D003198:Computer Simulation; D000431:Ethanol / Q000378:metabolism*; D008954:Models, Biological; D010843:Pichia / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D014994:Xylose / Q000378:metabolism*
chemical_list: D000431:Ethanol; D014994:Xylose