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ORIGINAL RESEARCH article

Front. Fungal Biol.

Sec. Fungal Genomics and Evolution

This article is part of the Research TopicHighlights of the 17th European Conference on Fungal Genetics (Dublin, 2-5 March 2025)View all articles

Genome-resolved tracking of Penicillium commune in a bakery facility highlights long-term environmental persistence

Provisionally accepted
Annette  FagerlundAnnette Fagerlund*Charlotte  KummenCharlotte KummenAnette  Wold ÅsliAnette Wold ÅsliCathrine  Kure FinneCathrine Kure Finne
  • Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, Ås, Norway

The final, formatted version of the article will be published soon.

Mould spoilage is a major challenge in bakery production, yet the sources and persistence of contaminating strains remain poorly understood. We applied whole-genome sequencing (WGS) to 68 isolates from potato-cereal wraps and their production environment in a Norwegian bakery. Barcode-based identification using ITS, BenA, CaM, and RPB2 confirmed that 65 isolates belonged to the Penicillium commune / Penicillium fuscoglaucum lineage but could not fully resolve species status or resolve strain-level differences. Genome-wide comparison using Mash placed these isolates in a single clade within series Camembertiorum, distinct from cheese-associated taxa. SNP analysis revealed extremely low diversity within the main cluster (up to 60 SNPs after recombination filtering) and demonstrated that genetically similar strains persisted in the facility for 15 months, spanning multiple products and environmental samples. No consistent association with potato suppliers or production dates was detected, indicating that long-term environmental reservoirs were the main source of contamination. These findings show that persistent clonal lineages can survive routine cleaning in dry bakery environments, enabling recurrent contamination. WGS provided the strain-level resolution needed to uncover this persistence and clarify phylogenetic placement, underscoring its value for monitoring and controlling mould spoilage in food production.

Keywords: P. fuscoglaucum, P. commune, WGS, food spoilage, mould, Potato, Lompe, Lefse

Received: 24 Sep 2025; Accepted: 21 Nov 2025.

Copyright: © 2025 Fagerlund, Kummen, Åsli and Finne. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Annette Fagerlund, annette.fagerlund@nofima.no

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