title: Alcoholic fermentation by wild-type Hansenula polymorpha and Saccharomyces cerevisiae versus recombinant strains with an elevated level of intracellular glutathione.
abstract: The ability of baker's yeast Saccharomyces cerevisiae and of the thermotolerant methylotrophic yeast Hansenula polymorpha to produce ethanol during alcoholic fermentation of glucose was compared between wild-type strains and recombinant strains possessing an elevated level of intracellular glutathione (GSH) due to overexpression of the first gene of GSH biosynthesis, gamma-glutamylcysteine synthetase, or of the central regulatory gene of sulfur metabolism, MET4. The analyzed strains of H. polymorpha with an elevated pool of intracellular GSH were found to accumulate almost twice as much ethanol as the wild-type strain during glucose fermentation, in contrast to GSH1-overexpressing S. cerevisiae strains, which also possessed an elevated pool of GSH. The ethanol tolerance of the GSH-overproducing strains was also determined. For this, the wild-type strain and transformants with an elevated GSH pool were compared for their viability upon exposure to exogenous ethanol. Unexpectedly, both S. cerevisiae and H. polymorpha transformants with a high GSH pool proved more sensitive to exogenous ethanol than the corresponding wild-type strains.
authors.affiliation: University of Rzeszow, Cwiklinskiej 2, 35-601 Rzeszow, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Grabek-Lejko
authors.forename: Olena O
authors.initials: OO
authors.lastname: Kurylenko
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Sibirny
authors.forename: Vira M
authors.initials: VM
authors.lastname: Ubiyvovk
authors.forename: Michel
authors.initials: M
authors.lastname: Penninckx
authors.forename: Andriy A
authors.initials: AA
authors.lastname: Sibirny
mesh_terms: D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D005721:Glutamate-Cysteine Ligase / Q000235:genetics / Q000378:metabolism; D005978:Glutathione / Q000096:biosynthesis*; D010843:Pichia / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D014994:Xylose / Q000378:metabolism
chemical_list: D000431:Ethanol; D014994:Xylose; D005721:Glutamate-Cysteine Ligase; D005978:Glutathione; D005947:Glucose