# Hanseniaspora uvarum and Hanseniaspora opuntiae differ in their growth and in the production of volatile organic compounds in wine

## TL;DR

This study compares two wine yeast species, H. uvarum and H. opuntiae, finding differences in their growth and fermentation byproducts, which could affect wine composition.

## Contribution

The study reveals distinct volatile compound production and growth patterns between two invasive Hanseniaspora species in wine fermentation.

## Key findings

- H. opuntiae produces more 2-phenylethyl acetate, while H. uvarum produces more glycerol during fermentation.
- Fermentation products differ between the two species depending on the medium and inoculum ratio.
- H. opuntiae may significantly influence wine composition if it replaces H. uvarum on grape berries.

## Abstract

In recent years, Hanseniaspora uvarum has been partially replaced in Slovenian vineyards by the thermotolerant and invasive Hanseniaspora opuntiae. The fermentation capacity of both Hanseniaspora species was evaluated based on CO₂ release in synthetic and natural must. Additionally, co-inoculations of both strains with S. cerevisiae were carried out in Sauvignon Blanc must at different ratios (1:10 and 10:1). In all experiments, microbial populations were monitored, and the chemical and volatile profiles of the resulting wines were evaluated. During alcoholic fermentation (AF) with pure cultures, the fermentation kinetics of the two Hanseniaspora species were comparable, with CO2 release in natural and synthetic must being two to five times lower compared to AF with the S. cerevisiae. In mixed AF with Hanseniaspora species and S. cerevisiae, there were no significant differences in fermentation capacity at the end of the fermentation compared to S. cerevisiae AF. However, the growth rate appears to be lower in H. opuntiae than in H. uvarum under oenological conditions. The results also showed that the formation of fermentation products differed between the two Hanseniaspora species in pure or mixed cultures, depending on the fermentation medium and inoculum ratio. H. opuntiae was a major producer of 2-phenylethyl acetate, and H. uvarum was a major producer of glycerol during alcoholic fermentation with natural must. The same tendency was observed for isoamyl acetate and ethyl acetate. We can conclude that H. opuntiae could become an important trigger for changes in wine composition if H. uvarum is further replaced on grape berries.

• In mixed AF, there was no antagonism between Hanseniaspora and Saccharomyces strains

• The concentrations of fermentation products differed between Hanseniaspora species.

• H. opuntiae could influence changes in wine composition produced by non-inoculated AF.

The online version contains supplementary material available at 10.1007/s00253-026-13800-6.