Poster Presentation 27th Annual Lorne Proteomics Symposium 2022

Fermenting yeasts and where to find them (#132)

Edward Kerr 1 , Mark Howes 2 , Ben Schulz 1
  1. University of Queensland, Brisbane, QLD, Australia
  2. Newstead Brewing Company, Brisbane, QLD, Australia

Beer is typically made using fermentation with Saccharomyces cerevisiae or Saccharomyces pastorianus, domesticated brewing yeasts. Historically, wild, non-Saccharomyces yeasts have also been frequently used in mixed culture fermentations to provide interesting and unique flavours to beer. However, brewing using mixed cultures or by spontaneous fermentation makes reproducing flavours and beer styles extremely difficult. Here, we describe a pipeline from collection of native wild yeast from plant material to the characterisation and commercial scale production of beer using wild yeast. We isolated 23 wild yeast strains, performed fermentation assays and measured ethanol production. We used growth assays, proteomics, metabolomics, and genomics to understand the sugar and amino acid utilisation profiles of two candidate production strains of wild Torulaspora compared to commonly used craft beer brewing yeast US05, and a poorly performing wild strain of the same genus. We then investigated media composition and culture condition parameters that could affect growth, and modifications that could be made at a commercial scale to promote effective fermentation and product quality.