title: Genomic expression program of Saccharomyces cerevisiae along a mixed-culture wine fermentation with Hanseniaspora guilliermondii.
abstract: BACKGROUND
  The introduction of yeast starter cultures consisting in a blend of Saccharomyces cerevisiae and non-Saccharomyces yeast strains is emerging for production of wines with improved complexity of flavor. The rational use of this approach is, however, dependent on knowing the impact that co-inoculation has in the physiology of S. cerevisiae. In this work the transcriptome of S. cerevisiae was monitored throughout a wine fermentation, carried out in single culture or in a consortium with Hanseniaspora guilliermondii, this being the first time that this relevant yeast-yeast interaction is examined at a genomic scale.
  
  
  RESULTS
  Co-inoculation with H. guilliermondii reduced the overall genome-wide transcriptional response of S. cerevisiae throughout the fermentation, which was attributable to a lower fermentative activity of S. cerevisiae while in the mixed-fermentation. Approximately 350 genes S. cerevisiae genes were found to be differently expressed (FDR < 0.05) in response to the presence of H. guilliermondii in the fermentation medium. Genes involved in biosynthesis of vitamins were enriched among those up-regulated in the mixed-culture fermentation, while genes related with the uptake and biosynthesis of amino acids were enriched among those more expressed in the single-culture. The differences in the aromatic profiles of wines obtained in the single and in the mixed-fermentations correlated with the differential expression of S. cerevisiae genes encoding enzymes required for formation of aroma compounds.
  
  
  CONCLUSIONS
  By integrating results obtained in the transcriptomic analysis performed with physiological data our study provided, for the first time, an integrated view into the adaptive responses of S. cerevisiae to the challenging environment of mixed culture fermentation. The availability of nutrients, in particular, of nitrogen and vitamins, stands out as a factor that may determine population dynamics, fermentative activity and by-product formation.
authors: Escola de Ciências da Vida e Ambiente, Universidade de Trás-os-Montes e Alto Douro, Vila Real, Portugal. crbarbosa@utad.pt.
authors: Catarina
authors: C
authors: Barbosa
authors: Escola de Ciências da Vida e Ambiente, Universidade de Trás-os-Montes e Alto Douro, Vila Real, Portugal. afaia@utad.pt.|BioISI-Biosystems and Integrative Sciences Institute, Campo Grande, Lisbon, Portugal. afaia@utad.pt.
authors: Arlete
authors: A
authors: Mendes-Faia
authors: Escola de Ciências da Vida e Ambiente, Universidade de Trás-os-Montes e Alto Douro, Vila Real, Portugal. plage@utad.pt.
authors: Patrícia
authors: P
authors: Lage
authors: iBB-Institute for Bioengineering and Biosciences, Avenida Rovisco Pais, 1049-001, Lisbon, Portugal. nuno.mira@tecnico.ulisboa.pt.|Department of Bioengineering, Instituto Superior Técnico, Avenida Rovisco Pais, 1049-001, Lisbon, Portugal. nuno.mira@tecnico.ulisboa.pt.
authors: Nuno P
authors: NP
authors: Mira
authors: Escola de Ciências da Vida e Ambiente, Universidade de Trás-os-Montes e Alto Douro, Vila Real, Portugal. anamf@utad.pt.|BioISI-Biosystems and Integrative Sciences Institute, Campo Grande, Lisbon, Portugal. anamf@utad.pt.
authors: Ana
authors: A
authors: Mendes-Ferreira
mesh_terms: D018920:Coculture Techniques; D005285:Fermentation; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D023281:Genomics; D055321:Hanseniaspora / Q000378:metabolism*; D056265:Microbial Interactions; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D014920:Wine