Climate changes are affecting both our lives and the environment we live in. Due to increasingly high temperatures and unusual weather patterns, the spread of invasive species is easier, potentially posing a threat of outcompeting indigenous ones. This includes wine yeasts of the Hanseniaspora genus. H. opuntiae, being better adapted to higher temperatures and other stresses encountered during wine production, can outcompete the dominant H. uvarum in our vineyards. Due to adaptations to higher temperatures and other stress factors encountered during grape and wine production, H. opuntiae is capable of prevailing over the previously autohtonous H. uvarum in our vineyards. To determine differences in sensitivity to stress conditions in vineyards, we measured the maximum specific growth rate, yield, and doubling time of 75 strains from both species on 14 different carbon sources and in the presence of 12 growth inhibitors or fungicides at minimal inhibitory concentrations. Prior to testing, the species identity of the strains was confirmed through sequencing of the ITS region. Phenotypic test results revealed differences among the strains of both species in specific growth rate, yield, and doubling time, which we statistically evaluated. Yield indicated that native H. uvarum yeasts were more resistant to the fungicide azoxystrobin compared to H. opuntiae. Conversely, in media supplemented with the fungicide cyprodinil, H. opuntiae strains exhibited nearly three times faster doubling times than H. uvarum strains. We also compared phenotypic differences between vineyard isolates and wild-origin strains of both tested species H. uvarum and H. opuntiae. Wild-origin strains were more sensitive to sodium dodecyl sulfate (SDS) but less sensitive to the fungicide pyrimethanil. From these results, we cannot confirm that vineyard strains of H. uvarum and H. opuntiae are better adapted to the selective pressures in vineyards and are thus less sensitive to them than wild isolates.
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