Vitis species, vintage, and alcoholic fermentation do not drive population structure in Starmerella bacillaris (synonym Candida zemplinina) species

Abstract

The yeast species Starmerella bacillaris (synonym Candida zemplinina) is widely associated with oenological ecosystems and is frequently isolated from grape and grape must. Previous work showed that the genetic diversity of this species is high in wine environments and it is shaped by geographic location. Most analysed C. zemplinina strains, however, have been isolated from Vitis vinifera, disregarding the existence of other worldwide-distributed Vitis species used in winemaking. In this work, we address the impact of the Vitis species and geographic location on the genetic diversity of C. zemplinina. Microsatellite genotyping analysis was applied to two remarkable populations of C. zemplinina from Argentina and Portugal (Azores Archipelago), isolated from neighbouring V. vinifera and Vitis labrusca vineyards. The study also included a large population of previously characterized worldwide-isolated C. zemplinina strains. Genetic analyses confirmed that geographic localization significantly shaped the genetic diversity of C. zemplinina. No genetic differentiation on the basis of the Vitis species was recorded, indicating that C. zemplinina populations from neighbouring V. vinifera and V. labrusca vineyards are genetically homogeneous.In addition, no impact of the vintage was found on the C. zemplinina populations being both highly diversified and homogeneous during initial stages of alcoholic fermentation. Altogether, these results confirmed that winemaking-related factors (i.e., vintage, Vitis species, and alcoholic fermentation) do not impact the genetic diversity of C. zemplinina and that only geographic localization significantly shapes this yeast species.

Genetic, Physiological, and Industrial Aspects of the Fructophilic Non-Saccharomyces Yeast Species, Starmerella bacillaris

“…The chromosome alignments analyzed showed a general synteny between both genomes, with a high number of single nucleotide polymorphisms (SNPs) (i.e., 33,771 variants among 1146 putative genes) [29]. These observations highlight the large potential biodiversity among wild isolates of S. bacillaris, as has been reported by other authors [37][38][39].…”

“…This study also showed that Argentinian S. bacillaris populations are more differentiated from European populations than S. bacillaris populations within Europe [37]. In addition, no evidence of genetic differentiation based on the Vitis species or vintages, nor an evolving S. bacillaris population during alcoholic fermentation was found [37]. Overall, no genetic signature of S. bacillaris strains was found associated with different vintages, Vitis species, vineyards, and/or wineries, indicating that winemaking-related factors (i.e., Vitis species, vintage, alcoholic fermentation, and/or wineries) do not impact S. bacillaris population structure [37,38].…”

“…Argentina (Colonia Caroya, Córdoba) [11,12] and Portugal (Azores Archipelago) [4,5], reinforced the impact of geographic localization on S. bacillaris genetic population structure. This study also showed that Argentinian S. bacillaris populations are more differentiated from European populations than S. bacillaris populations within Europe [37]. In addition, no evidence of genetic differentiation based on the Vitis species or vintages, nor an evolving S. bacillaris population during alcoholic fermentation was found [37].…”

“…In addition, no evidence of genetic differentiation based on the Vitis species or vintages, nor an evolving S. bacillaris population during alcoholic fermentation was found [37]. Overall, no genetic signature of S. bacillaris strains was found associated with different vintages, Vitis species, vineyards, and/or wineries, indicating that winemaking-related factors (i.e., Vitis species, vintage, alcoholic fermentation, and/or wineries) do not impact S. bacillaris population structure [37,38]. Thus, S. bacillaris is not under selective pressure in winemaking environments, representing an interesting model of a non-domesticated ubiquitous wine yeast species [37].…”

“…Among these, restriction fragment length polymorphism (RFLP) analyses of 5.8S-ITS regions (Table 1) enable the identification of S. bacillaris isolates to species level, as well as differentiation of this yeast species from the close species, Candida stellata (i.e., DraI and MboI enzymes) [33] and Starmerella bombicola [45] (Table 1). Other molecular strategies have been used to characterize S. bacillaris to strain level, including SAU-PCR, RAPD-PCR, micro/minisatellites, and Rep-PCR, as well as AFLP-fingerprinting, mt-DNA-RFLP, and TRtRNA-PCR analyses [8,16,17,23,37,38,46]. Fingerprinting analyses, using SAU-PCR and Rep-PCR, have enabled recognition of genetic similarity between isolates from different sources [17,23] (Figure 1).…”