title: Candida zemplinina can reduce acetic acid produced by Saccharomyces cerevisiae in sweet wine fermentations.
abstract: In this study we investigated the possibility of using Candida zemplinina, as a partner of Saccharomyces cerevisiae, in mixed fermentations of must with a high sugar content, in order to reduce its acetic acid production. Thirty-five C. zemplinina strains, which were isolated from different geographic regions, were molecularly characterized, and their fermentation performances were determined. Five genetically different strains were selected for mixed fermentations with S. cerevisiae. Two types of inoculation were carried out: coinoculation and sequential inoculation. A balance between the two species was generally observed for the first 6 days, after which the levels of C. zemplinina started to decrease. Relevant differences were observed concerning the consumption of sugars, the ethanol and glycerol content, and acetic acid production, depending on which strain was used and which type of inoculation was performed. Sequential inoculation led to the reduction of about half of the acetic acid content compared to the pure S. cerevisiae fermentation, but the ethanol and glycerol amounts were also low. A coinoculation with selected combinations of S. cerevisiae and C. zemplinina resulted in a decrease of ~0.3 g of acetic acid/liter, while maintaining high ethanol and glycerol levels. This study demonstrates that mixed S. cerevisiae and C. zemplinina fermentation could be applied in sweet wine fermentation to reduce the production of acetic acid, connected to the S. cerevisiae osmotic stress response.
authors.affiliation: DIVAPRA, Agricultural Microbiology and Food Technology Sector, University of Turin, Turin, Italy.
authors.forename: Kalliopi
authors.initials: K
authors.lastname: Rantsiou
authors.forename: Paola
authors.initials: P
authors.lastname: Dolci
authors.forename: Simone
authors.initials: S
authors.lastname: Giacosa
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Torchio
authors.forename: Rosanna
authors.initials: R
authors.lastname: Tofalo
authors.forename: Sandra
authors.initials: S
authors.lastname: Torriani
authors.forename: Giovanna
authors.initials: G
authors.lastname: Suzzi
authors.forename: Luca
authors.initials: L
authors.lastname: Rolle
authors.forename: Luca
authors.initials: L
authors.lastname: Cocolin
mesh_terms: D019342:Acetic Acid / Q000378:metabolism*; D002175:Candida / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D005990:Glycerol / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D013997:Time Factors; D014920:Wine / Q000382:microbiology*
chemical_list: D000431:Ethanol; D005990:Glycerol; D019342:Acetic Acid