Brettanomyces bruxellensis wine isolates show high geographical dispersal and long remanence in cellars

Abstract

23Brettanomyces bruxellensis is the main wine spoiler yeast all over the world, yet the structuration of 24 the populations associated with winemaking remains elusive. In this work, we considered 1411 wine 25 isolates from 21 countries that were genotyped using twelve microsatellite markers. We confirmed that 26 B. bruxellensis isolates from wine environments show high genetic diversity, with 58 and 42% of 27 triploid and diploid individuals respectively distributed in 5 main genetic groups. The distribution in 28 the genetic groups varied greatly depending on the country and/or the wine-producing region. 29However, the two wine triploid groups showing sulfite resistance/tolerance were identified in almost 30 all regions/countries. Genetically identical isolates were also identified. The analysis of these clone 31 groups revealed that a given genotype could be isolated repeatedly in the same winery over decades, 32demonstrating unsuspected remanence ability. Besides cellar residency, a great geographic dispersal 33 was also evidenced, with some genotypes isolated in wines from different continents. Finally, the 34 study of old isolates and/or isolates from old vintages revealed that only the diploid groups were 35 identified prior 1990 vintages. The triploid groups were identified in subsequent vintages, and their 36 proportion has increased steadily these last decades, suggesting adaptation to winemaking practices 37 such as sulfite use. A possible evolutionary scenario explaining these results is discussed. 38 39 3 40

Formation of Aromatic and Flavor Compounds in Wine: A Perspective of Positive and Negative Contributions of Non-SaccharomycesYeasts

“…From the genetic point of view, there is a great intraspecific diversity of strains of B. bruxellensis [120][121][122][123], which translates into the different phenotypes of production of reported volatile phenols. The number of chromosomes in this species can vary between 4 and 9, with chromosome sizes in the range of 1 to 6 Mb, and total genome size between 20 and 30 Mb [124,125].…”