# The Impact of Biocontrol Agents on the Metabolome of Penicillium nordicum Strains and Its Relation to Ochratoxin A Production on Dry-Cured Ham

## TL;DR

This study explores how biocontrol agents affect the metabolism of Penicillium nordicum molds on dry-cured ham and their ability to produce a harmful toxin.

## Contribution

The study reveals how specific biocontrol agents alter the metabolome of two P. nordicum strains, influencing toxin production pathways.

## Key findings

- Biocontrol agents altered the metabolomes of P. nordicum strains, affecting phenylalanine catabolism and branched-chain amino acid biosynthesis.
- The two P. nordicum strains showed distinct metabolomic profiles even under identical conditions.
- BCAs show potential for reducing ochratoxin A production but require testing against diverse toxigenic molds.

## Abstract

Throughout the process of dry-cured ham, moulds such as P. nordicum, a producer of ochratoxin A (OTA), grow on its surface. The use of combined biocontrol agents (BCAs) is a promising strategy for controlling this hazard. The goal of this study is to assess the effect of D. hansenii, S. xylosus, and P. chrysogenum as BCAs on the metabolome of two strains of P. nordicum and to understand the differences between both strains. Each ochratoxigenic strain was inoculated both individually and in combination with the BCAs onto ham for 30 days under the environmental conditions experienced during traditional ripening. Untargeted metabolomics was performed through mass spectrometry using a Q-Exactive Plus Orbitrap. The BCAs caused alterations in the metabolomes of both ochratoxigenic moulds, mainly in phenylalanine catabolism and the valine, leucine, and isoleucine biosynthesis pathways, although with some differences. In the absence of the BCAs, the metabolomes of both types of P. nordicum were globally changed, despite these being moulds of the same species. In conclusion, these data help us to understand the differences between OTA-producing strains in dry-cured ham and confirm the need to demonstrate the efficacy of BCAs against a wide range of toxigenic moulds before they can be used to minimise OTA contamination in the meat industry.