title: Bioethanol strains of Saccharomyces cerevisiae characterised by microsatellite and stress resistance.
abstract: Strains of Saccharomyces cerevisiae may display characteristics that are typical of rough-type colonies, made up of cells clustered in pseudohyphal structures and comprised of daughter buds that do not separate from the mother cell post-mitosis. These strains are known to occur frequently in fermentation tanks with significant lower ethanol yield when compared to fermentations carried out by smooth strains of S. cerevisiae that are composed of dispersed cells. In an attempt to delineate genetic and phenotypic differences underlying the two phenotypes, this study analysed 10 microsatellite loci of 22 S. cerevisiae strains as well as stress resistance towards high concentrations of ethanol and glucose, low pH and cell sedimentation rates. The results obtained from the phenotypic tests by Principal-Component Analysis revealed that unlike the smooth colonies, the rough colonies of S. cerevisiae exhibit an enhanced resistance to stressful conditions resulting from the presence of excessive glucose and ethanol and high sedimentation rate. The microsatellite analysis was not successful to distinguish between the colony phenotypes as phenotypic assays. The relevant industrial strain PE-2 was observed in close genetic proximity to rough-colony although it does not display this colony morphology. A unique genetic pattern specific to a particular phenotype remains elusive.
authors.affiliation: Universidade Federal de São Carlos (Centro de Ciências Agrarias), Departamento Tecnologia Agroindustrial e Socio-Economia Rural, Laboratório de Microbiologia Agrícola e Molecular, Araras, SP, Brazil.
authors.forename: Vanda Renata
authors.initials: VR
authors.lastname: Reis
authors.affiliation: Universidade Estadual Paulista, Instituto de Biociencias de Botucatu, Departamento Parasitologia, Botucatu, SP, Brazil.
authors.forename: Ana Teresa Burlamaqui Faraco
authors.initials: ATBF
authors.lastname: Antonangelo
authors.affiliation: Universidade Federal de São Carlos (Centro de Ciências Agrarias), Departamento Tecnologia Agroindustrial e Socio-Economia Rural, Laboratório de Microbiologia Agrícola e Molecular, Araras, SP, Brazil.
authors.forename: Ana Paula Guarnieri
authors.initials: APG
authors.lastname: Bassi
authors.affiliation: Genotyping Laboratório de Biotecnologia Ltda, Botucatu, SP, Brazil.
authors.forename: Débora
authors.initials: D
authors.lastname: Colombi
authors.affiliation: Universidade Federal de São Carlos (Centro de Ciências Agrarias), Departamento Tecnologia Agroindustrial e Socio-Economia Rural, Laboratório de Microbiologia Agrícola e Molecular, Araras, SP, Brazil. Electronic address: antonini@cca.ufscar.br.
authors.forename: Sandra Regina
authors.initials: SR
authors.lastname: Ceccato-Antonini
mesh_terms: D000431:Ethanol / Q000378:metabolism*; D014644:Genetic Variation; D005838:Genotype; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D018895:Microsatellite Repeats; D010641:Phenotype; D012441:Saccharomyces cerevisiae / Q000145:classification / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D013312:Stress, Physiological
chemical_list: D000431:Ethanol; D005947:Glucose
keywords: Contaminants; Fermentation; Microsatellite; Stresses; Yeasts