Metagenomic Approaches to Investigate the Contribution of the Vineyard Environment to the Quality of Wine Fermentation: Potentials and Difficulties

Abstract

The winemaking is a complex process that begins in the vineyard and ends at consumption moment. Recent reports have shown the relevance of microbial populations in the definition of the regional organoleptic and sensory characteristics of a wine. Metagenomic approaches, allowing the exhaustive identification of microorganisms present in complex samples, have recently played a fundamental role in the dissection of the contribution of the vineyard environment to wine fermentation. Systematic approaches have explored the impact of agronomical techniques, vineyard topologies, and climatic changes on bacterial and fungal populations found in the vineyard and in fermentations, also trying to predict or extrapolate the effects on the sensorial characteristics of the resulting wine. This review is aimed at highlighting the major technical and experimental challenges in dissecting the contribution of the vineyard and native environments microbiota to the wine fermentation process, and how metagenomic approaches can help in understanding microbial fluxes and selections across the environments and specimens related to wine fermentation.

Keywords: bacteria; environment; fungi; metagenomics; vineyard; wine.

Figure 1

Characterizing and comparing populations. (A) Examples of three populations, letters refer to different taxa, the letter size indicating the abundance of the taxon in the sample. (B) alpha diversities (richness, Shannon index, and Simpson index) calculated for the populations shown in (A). (C) taxa relative abundances of the taxa composing the populations shown in (A). (D) taxa absolute abundances of the taxa composing the populations shown in panel (A).

Figure 2

Schematic representation of the factors known to influence the composition of microbial populations involved in wine fermentations. ¹(Bokulich et al., 2014); ²(Burns et al., 2015); ³(Grangeteau et al., 2017); ⁴(Pinto et al., 2014); ⁵(Miura et al., 2017); ⁶(Morrison-Whittle and Goddard, 2018); ⁷(Piao et al., 2015); ⁸(Stefanini et al., 2016).