title: Selection of Botrytis cinerea and Saccharomyces cerevisiae strains for the improvement and valorization of Italian passito style wines.
abstract: In order to improve the quality of Italian passito wine, produced from withered grapes that can be naturally infected by noble rot, in this study, a novel protocol was developed to select suitable cultures of both Botrytis cinerea to infect grapes (as noble rot) and of Saccharomyces cerevisiae to ferment grapes. A total of 16 B. cinerea isolated from withered grapes were typified by RAPD-PCR, and three representative strains were selected for physiological characterization. The strains showed different mycelial growth and enzymatic activities (i.e. polygalacturonase, protease, and laccase). A total of 15 yeasts were isolated from spontaneous fermented wines, these were identified as S. cerevisiae, and typified at strain level. Seven strains were selected according to RAPD-PCR profiles and tested for their fermentation performances. The effects of B. cinerea and S. cerevisiae cultures on the aroma profile of sweet style wine were preliminary evaluated fermenting artificially botrytized grapes induced with B. cinerea infection. The combination of selected fungi affected the aroma profile of wine according to the variation of the content of important molecules (i.e. alcohols, esters, and lactones). This study has provided valuable information to develop new natural cultures destined to induce grape botrytization and manage fermentation in passito winemaking.
authors.affiliation: Centro per la Sperimentazione in Vitivinicoltura, Provincia di Verona, Servizio Agricoltura, San Pietro in Cariano, Verona, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Azzolini
authors.forename: Emanuele
authors.initials: E
authors.lastname: Tosi
authors.forename: Stefano
authors.initials: S
authors.lastname: Faccio
authors.forename: Marilinda
authors.initials: M
authors.lastname: Lorenzini
authors.forename: Sandra
authors.initials: S
authors.lastname: Torriani
authors.forename: Giacomo
authors.initials: G
authors.lastname: Zapparoli
mesh_terms: D020171:Botrytis / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism / Q000502:physiology; D004271:DNA, Fungal / Q000235:genetics; D004798:Enzymes / Q000378:metabolism; D005285:Fermentation; D007558:Italy; D058889:Molecular Typing; D025282:Mycelium / Q000254:growth & development; D016533:Mycological Typing Techniques; D019105:Random Amplified Polymorphic DNA Technique; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism / Q000502:physiology; D012641:Selection, Genetic; D014920:Wine / Q000382:microbiology*
chemical_list: D004271:DNA, Fungal; D004798:Enzymes
keywords: fermentation; molds; passito wines; strain selection; wine aroma; yeasts