dsm-firmenich uncovers novel bacterial defence mechanisms to combat phage contamination in dairy fermentation
dsm-firmenich has announced a significant development in dairy culture technology following collaborative research with APC Microbiome Ireland and INRAE that reveals how bacteria defend themselves against bacteriophages during fermentation processes.
The findings, published in the Proceedings of the National Academy of Sciences (PNAS), [1] detail the discovery and characterisation of 13 previously unknown antiphage systems in Lactococcus lactis, the primary bacterial species used in commercial dairy fermentation. The research provides new understanding of how these defence mechanisms operate and how phages evolve to circumvent them.
Understanding phage evasion strategies
Through genomic analysis of 66 phage mutants that had successfully overcome bacterial resistance, researchers identified 15 viral genes involved in the evasion process. This molecular-level insight into phage adaptation strategies could enable more targeted approaches to culture protection in industrial settings.
A particularly notable discovery is the characterisation of a novel defence system called Audmula. This mechanism protects bacterial cultures by modifying the host’s cell wall, effectively trapping phages inside and preventing their spread throughout the fermentation environment. According to the research team, this represents the first observation of this particular mode of action.
“Over the past decade, we’ve learned that bacterial antiviral defences form an arsenal far more diverse and complex than we ever imagined,” said Prof. Douwe van Sinderen, senior author of the study. “With this study, we’re finally beginning to understand how those defences function – and how viruses manage to evade them. In practical terms, these findings pave the way for next-generation starter cultures designed to withstand the phage challenges facing today’s dairy fermentations.”
Industrial application
Bacteriophage contamination remains a significant challenge in industrial dairy production, causing fermentation failures, product losses, and quality issues. The research provides a foundation for developing more resilient culture blends and rotation schemes designed to counter phage outbreaks.
Dsm-firmenich contributed proprietary Lactococcus strains, genomic data, and phages sourced from operational dairy environments to ensure the research reflected real-world production conditions.
“By decoding the complex relationship between cultures and phages, we’re turning cutting-edge science into competitive advantage – giving us the tools to design ultra-robust culture blends and rotation schemes, empowering producers to take control of fermentation across dairy, plant-based, probiotics, and emerging biotechnologies,” said Noël van Peij, co-author and principal scientist at dsm-firmenich. “This is science delivering value for the cheese and fermented milk products market, where it matters most.”
Evandro Oliveira de Souza, global senior vice-president cheese business unit at dsm-firmenich, added: “These findings demonstrate the power of combining our in-house scientific expertise with world-class research partnerships to solve real industry challenges. By applying these insights to our culture development, we’re adding to the unique depth and breadth of our dairy portfolio and strengthening our ability to deliver more resilient and reliable fermentation performance for dairy producers worldwide.”
The company intends to incorporate these findings into its culture development programmes to support the delivery of more phage-resistant solutions for dairy manufacturers.
For more information, visit: www.dsm-firmenich.com
Reference
1. C. Mosterd, A. Grafakou, G. Ortiz Charneco, et. al. (2025) The great phage escape: Activating and escaping lactococcal antiphage systems, Proc. Natl. Acad. Sci. U.S.A. 122 (24) e2426508122, https://doi.org/10.1073/pnas.2426508122
