title: Asymmetric synthesis with immobilized yeast in organic solvents: equilibrium conversion and effect of reactant partitioning on whole cell biocatalysis.
abstract: A newly isolated strain of the yeast Saccharomyces cerevisiae is investigated for the biocatalytic reduction of ketones and the oxidation of alcohols in organic solvents. The yeast cells are immobilized by entrapment within calcium alginate beads and are found to possess the ability to stereoselectively reduce prochiral ketones and oxidize chiral alcohols to equilibrium conversions. The effect of reactant partitioning on the initial rate of the reactions is also investigated. The observed initial rates are found to vary inversely with reactant partitioning between the organic solvent and the biocatalyst beads. A kinetic model is developed to describe the initial reaction rate of hexanone reduction as a function of substrate concentration within the alginate beads.
authors.affiliation: Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia 22904-4741, USA.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Gervais
authors.forename: Giorgio
authors.initials: G
authors.lastname: Carta
authors.forename: John L
authors.initials: JL
authors.lastname: Gainer
mesh_terms: D000438:Alcohols / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D002384:Catalysis; D018929:Cell Culture Techniques / Q000379:methods*; D018914:Cells, Immobilized / Q000145:classification / Q000378:metabolism; D003198:Computer Simulation; D007659:Ketones / Q000378:metabolism*; D008954:Models, Biological; D010084:Oxidation-Reduction; D012441:Saccharomyces cerevisiae / Q000145:classification / Q000254:growth & development* / Q000378:metabolism*; D013237:Stereoisomerism
chemical_list: D000438:Alcohols; D007659:Ketones