Support to take up INRA/ Agreenskills + fellowship in Montpellier, France
Abstract
The activity of yeasts in wine fermentations directly contributes to wine quality, but the source and movement of these yeasts in vineyard and winery environments has not been resolved. This study investigates the yeast species associated with a insect vector to help understand yeast dispersal and persistence. Drosophila are commonly found in vineyards and Drosophila and yeasts have a known mutualistic relationship in other ecosystems. Drosophilids were collected from vineyards, marc piles and wineries during the grape harvest. Captured flies were identified morphologically to and their associated yeasts were identified. Of the 296 Drosophila flies captured in this study the species identified were Drosophila melanogaster, Drosophila simulans, Drosophila hydei, and Scaptodrosophila lativittata. These flies were associated with the yeasts Metschnikowia pulcherrima, Hanseniaspora uvarum, Torulaspora delbrueckii and Hanseniaspora valbyensis. The diversity of yeasts and Drosophila species differed between collection locations (vineyard and marc; R=0.588 for Drosophila and R= 0.644 for yeasts). Surprisingly, the primary wine fermentation yeast, Saccharomyces cerevisiae was not isolated in this study. Drosophila flies are preferentially associated with different species of yeasts in the vineyard and winery environment and this association may help movement and dispersal of yeast species in the vineyard and winery ecosystem.
Summary
This travel grant was used to support the trip of Kate Howell to take up a fellowship awarded by the European Union and INRA, in Montpellier France. The contribution by AGWA was to offset travel expenses not covered by my existing funding. My fellowship at INRA was to look at the populations of Drosophila and their yeast symbionts in French vineyards, with a particular focus on the pest species of Drosophila, spotted wing Drosophila (Drosophila suzukii). The work was carried out in two laboratories in Montpellier and surrounds; in UMR Sciences pour l’Oenologie (SPO) under the direction of Dr. Sylvie Dequin and at UMR Centre de Biologie et Gestion de Populations (CBPG) under the direction of Dr. Simon Fellous. My focus was understanding the microbial partners of Drosophila and I used both culture-dependent and culture-independent methods to characterise these communities. I tested how the flies are attracted to yeast substrates by correlating attractiveness with volatile production. The results are still forthcoming, but will contribute to the fundamental biological knowledge of this pest, by understanding the difference in microbial communities in different regional populations.