# Prey preference and cell wall-mediated resistance shape predation efficiency in Saccharomycopsis schoenii

## TL;DR

This study explores how Saccharomycopsis schoenii, a predatory yeast, interacts with wine yeast species, focusing on prey preferences and cell wall features that influence predation efficiency.

## Contribution

The study identifies cell wall chitin and structural features as key factors in prey resistance to predation by S. schoenii.

## Key findings

- Saccharomyces cerevisiae is highly susceptible to predation by S. schoenii, while Torulaspora delbrueckii shows resistance.
- Cell wall chitin levels in S. cerevisiae mutants influence resistance to predation, but broader structural features also play a role.
- Prey adhesion traits, such as Flo-adhesins, do not significantly affect predation outcomes.

## Abstract

Microbial antagonism, including predation and competition, shapes microbial community diversity and dynamics. Saccharomycopsis schoenii, a unicellular predatory yeast, serves as a distinct model for bona fide fungal predation, characterized by penetration pegs that enable predation. This study examined prey preferences of S. schoenii within wine-associated yeast consortia and assessed the role of prey adhesion and cell wall features in modulating predation efficiency. Predation assays revealed species-specific dynamics, with Saccharomyces cerevisiae showing pronounced susceptibility and Torulaspora delbrueckii displaying resistance indicative of density-dependent prey switching. Expression of prey Flo-adhesins in S. cerevisiae did not affect predation outcomes, highlighting that prey adhesion phenotypes are not primary determinants of susceptibility. In contrast, S. cerevisiae VIN13-related mutant strains with increased cell wall chitin showed variable resistance phenotypes, suggesting that chitin contributes to resistance, but that broader cell wall remodelling and structural features are relevant factors independent of chitin levels. While these findings provide a mechanistic framework for understanding predator–prey interactions and prey resistance, the ecological and evolutionary significance of these interactions remains uncertain due to the rarity of Saccharomycopsis species in natural communities. Ultimately, these results emphasize the importance of integrating laboratory and ecological perspectives to fully comprehend the evolutionary implications of fungal predatory behaviour.

The predation efficiency of Saccharomycopsis schoenii against selected wine yeast species as prey, as well as the impact on predation efficiency of prey cell wall-related phenotypes, was investigated.