Revealing the Yeast Diversity of the Flor Biofilm Microbiota in Sherry Wines Through Internal Transcribed Spacer-Metabarcoding and Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry

Abstract

Flor yeast velum is a biofilm formed by certain yeast strains that distinguishes biologically aged wines such as Sherry wine from southern Spain from others. Although Saccharomyces cerevisiae is the most common species, 5.8 S-internal transcribed spacer (ITS) restriction fragment length polymorphism analyses have revealed the existence of non-Saccharomyces species. In order to uncover the flor microbiota diversity at a species level, we used ITS (internal transcribed spacer 1)-metabarcoding and matrix-assisted laser desorption/Ionization time of flight mass spectrometry techniques. Further, to enhance identification effectiveness, we performed an additional incubation stage in 1:1 wine:yeast extract peptone dextrose (YPD) before identification. Six species were identified: S. cerevisiae, Pichia manshurica, Pichia membranifaciens, Wickerhamomyces anomalus, Candida guillermondii, and Trichosporon asahii, two of which were discovered for the first time (C. guillermondii and Trichosporon ashaii) in Sherry wines. We analyzed wines where non-Saccharomyces yeasts were present or absent to see any potential link between the microbiota and the chemical profile. Only 2 significant volatile chemicals (out of 13 quantified), ethanol and ethyl lactate, and 2 enological parameters (out of 6 quantified), such as pH and titratable acidity, were found to differ in long-aged wines. Although results show a low impact where the non-Saccharomyces yeasts are present, these yeasts isolated from harsh environments (high ethanol and low nutrient availability) could have a potential industrial interest in fields such as food microbiology and biofuel production.

Estudio microbiológico, químico y sensorial de vinos tipo fino obtenidos de solera con 14% v/v de etanol

“…Los análisis microbiológicos se centraron en el aislamiento, identificación y caracterización de levaduras no-Sacccharomyces. Estas levaduras se han detectado en todos los ambientes de las bodegas [6]. El estudio microbiológico comparativo entre botas de vinos con diferente contenido alcohólico no difirió en gran medida, siendo la especie Torulaspora delbrueckii, la levadura no-Saccharomyces que más se detectó.…”

“…Los medios de cultivo usados fueron agar YPD (2% glucosa; 2% peptona; 1% extracto de levadura; 2% agar), medio agar lisina (OXOID CM0191), medio agar WL (OXOID CM0501), medio para detección de actividad β-glucosidasa, medio para caracterizar fenotipo killer. La identificación se realizó mediante MALDI-Biotyper [6].…”

Monitoring potentially pathogenic protists in sewage sludge using Metataxonomics

“…Metataxonomic approaches have proven to be a valuable tool in the study of bacterial ( Bedoya et al, 2019 , Bedoya et al, 2020 ; Xiong et al, 2021 ) and fungal diversity ( Carbonero-Pacheco et al, 2022 ; Peñuela-Martínez et al, 2023 ), in some cases even displacing classical microbiological techniques such as culture and direct visualization. Nonetheless, the application of this technology to protists has been slow but steady, and recent works have shown its effectiveness and advantages over traditional microbiological analysis ( Garner et al, 2021 ; Gu et al, 2021 ; Chihi et al, 2022 ; Sengupta et al, 2022 ).…”

Adaptación y desarrollo del velo de flor en vinos “sobretablas” de la D.O. Jerez-Xèrés-Sherry fortificados con alcoholes no vínicos

“…Mencionan que, el origen de estas levaduras es poco preciso, pues pueden provenir de las sobretablas, el vino joven utilizado para volver a llenar las criaderas, adaptándose a estos entornos cambiantes que pueden estresar a las levaduras. Además, se ve favorecido su crecimiento al alimentarse de las proteínas extracelulares y otros nutrientes de levaduras que perecieron [14]. En un estudio más reciente llevado a cabo por Ruiz-Muñoz y colaboradores [15], se ha demostrado que las levaduras no-Saccharomyces no actúan como contaminantes ocasionales de vinos Finos, sino que también forman parte del velo de flor.…”