# Compounds Derived from Tryptophan Metabolism in Torulaspora delbrueckii CBS1146T and Zygosaccharomyces bailii ATCC36947T

## TL;DR

This study explores how two non-Saccharomyces yeasts produce tryptophan-derived compounds in wine fermentation, revealing strain-specific differences and the impact of the fermentation environment.

## Contribution

The study reports the first identification of tryptophan-ethylester isomers in these yeasts and highlights the influence of the fermentation matrix on metabolite production.

## Key findings

- Torulaspora delbrueckii produced significant amounts of tryptophan-ethylester, linked to dTRP consumption.
- Zygosaccharomyces bailii synthesized diverse metabolites like 5OH-tryptophan and kynurenic acid.
- The fermentation matrix strongly influenced dTRP biosynthesis, enhancing TEE and kynurenic acid accumulation.

## Abstract

Yeast metabolism significantly contributes to functional beverage production by generating bioactive compounds such as tryptophan derivatives (dTRPs). While Saccharomyces cerevisiae is traditionally used, non-Saccharomyces yeasts like Torulaspora delbrueckii and Zygosaccharomyces bailii are gaining interest for their ability to enhance aroma profiles and influence metabolite synthesis. This study evaluated the dTRP production of T. delbrueckii CBS1146T and Z. bailii ATCC36947T in synthetic medium and Cabernet Sauvignon must supplemented with 100 mg/L tryptophan. LC-MS/MS analysis revealed strain-dependent differences in metabolite profiles, with a predominance of kynurenine pathway compounds and the first identification of two tryptophan-ethylester (TEE) isomers. T. delbrueckii exhibited significant TEE production, correlating with the consumption of dTRPs; conversely, Z. bailii synthesized diverse metabolites, including 5OH-tryptophan and kynurenic acid. Notably, melatonin was not detected. The fermentation matrix strongly influenced dTRP biosynthesis, with must conditions enhancing TEE and kynurenic acid accumulation. These findings highlight the role of growth medium composition in modulating yeast metabolism and support the potential of non-Saccharomyces yeasts for functional beverage development.