# Zearalenone Biotransformation by Tibetan Plateau-Derived Yeast Hannaella zeae: Biological Pattern Elucidation, Metabolite Safety, and Environmental Tolerance

## TL;DR

A yeast from the Tibetan Plateau efficiently transforms the harmful compound zearalenone into safer metabolites, showing promise for detoxification in food and feed.

## Contribution

The study identifies a stress-tolerant yeast strain with a glycosylation-based detoxification mechanism for zearalenone.

## Key findings

- Hannaella zeae achieved 85.87% zearalenone transformation within 36 hours under optimal conditions.
- The yeast produced non-toxic glycosylated metabolites, confirmed by high-resolution mass spectrometry.
- H. zeae maintained high transformation efficiency under low temperature and acidic stress.

## Abstract

Zearalenone (ZEN) poses serious risks to human and animal health. Compared with physical and chemical methods, microbial transformation offers a safer and more sustainable strategy for ZEN detoxification. The yeast Hannaella zeae, isolated from the Qinghai–Tibet Plateau, showed the highest ZEN removal efficiency among 11 strains, achieving an 85.87% transformation rate within 36 h. Optimal conditions for ZEN transformation were determined by varying culture time, temperature, and pH. The products were putatively identified as zearalenone-14-β-D-glucopyranoside (C24H32O10) and zearalenone-16-β-D-glucopyranoside (C24H32O10) by UHPLC-Q-Orbitrap-HRMS. The safety of the mixed culture medium extract was further evaluated using a Caenorhabditis elegans model, showing significantly lower toxicity than untreated ZEN. H. zeae maintained high transformation efficiency under low temperature (57.48%) and acidic stress (47.10%), supported by active antioxidant enzymes (SOD, CAT, APX, GPx) and stress metabolites (trehalose, proline). Overall, this study identifies H. zeae as a promising, stress-tolerant biocontrol agent and elucidates its glycosylation-based detoxification mechanism, providing a foundation for future application in real food and feed systems.