Forest Oak Woodlands and Fruit Tree Soils Are Reservoirs of Wine-Related Yeast Species

• Autor(a) principal: Chandra, Mahesh
• Data de Publicação: 2020
• Outros Autores: Mota, Mariana, Silva, Ana Carla, Malfeito-Ferreira, Manuel
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.5/22001
• topic: fruit tree; non-Saccharomyces species; oak tree; Saccharomyces cerevisiae; vineyard soil; yeast reservoirs

In this study, a large-scale sampling plan was performed over a period of four years in three different vineyards to evaluate the occurrence of wine-related yeast species in the soils underneath vines and forest oak and fruit trees close to the vineyards. Ascomycetous fermentative yeasts were present in 27% of 320 soil samples throughout the sampling years with incidences that could not be related to sampling season. Highest percentages of occurrence were found in soils under fig (76%), apple (73%) and oak trees (41-55%). Soils were less contaminated under vines (6%), while these yeasts were not recovered from soil underneath chestnut trees. Other soils showed intermediate percentages of occurrence. A total of 139 fermentative ascomycetes were identified, revealing 25 species. A total of 96 isolates corresponded to different non-Saccharomyces species and 43 isolates to 4 Saccharomyces species. Soils underneath fruit trees shared 11 different species. The most common isolates belonged to Lachancea thermotolerans and Torulaspora delbrueckii, while Sacharomyces paradoxus predominated in the soil underneath oak trees. S. cerevisiae was found in low percentage (7% of total isolates) during all sampling years under fruit trees but was not recovered from vineyard or oak tree soils. The wine spoilage species Zygosaccharomyces bailii was recovered only in one sample of vineyard soil. Our work clearly demonstrated that, for a given soil system, the species recovered vary strongly over the years thus suggesting the existence of complex yeast communities. In particular, the soils in the vicinity of vineyards were found to be natural reservoirs of yeast species of oenological interest