Fermentation has long been a cornerstone of human food culture, with yogurt representing one of its most iconic products. While industrial fermentation relies on standardized bacterial strains, traditional methods often harness diverse microbial communities from natural environments. In a groundbreaking study, Sinotte et al. (2025) explore the role of red wood ants (Formica rufa and F. polyctena) and their associated microbiota—collectively termed the “ant holobiont”—in initiating milk fermentation.
Ethnographic and Experimental Foundations
The research draws on ethnographic accounts from Bulgaria and Turkey, where ants and their nests were historically used to start yogurt fermentation. Fieldwork in Bulgaria confirmed that placing live ants in warm milk and incubating the mixture within an ant colony led to acidification and coagulation, producing a tangy, herbaceous yogurt.
Credit: David Zilber
Microbial Contributions
Using 16S rRNA metabarcoding and culturomics, the study identified lactic acid bacteria (LAB) such as Fructilactobacillus sanfranciscensis and Lactobacillus delbrueckii subsp. bulgaricus, as well as acetic acid bacteria like Oecophyllibacter saccharovorans, within the ants and resulting yogurts. These microbes contributed to the production of lactic, acetic, and formic acids, essential for flavor and preservation.
Enzymatic Activity and Texture
Proteomic analysis revealed that both ants and their microbes produce proteases capable of modifying milk proteins. Notably, ATP-dependent CLP proteases and zinc metalloproteases were detected, suggesting a role in casein breakdown and yogurt texturization.
Safety and Regulatory Considerations
While the study highlights the fermentative potential of ants, it also cautions against general use due to food safety risks, including the presence of parasites and the lack of EU approval for ants as food. Live ants produced the most consistent and desirable fermentation outcomes, whereas frozen or dehydrated ants led to variable microbiomes and potential contamination.
This research underscores the value of integrating traditional knowledge with modern microbiology. The ant holobiont offers a unique ecological niche for fermentative microbes, expanding the possibilities for novel food fermentations and deepening our understanding of biocultural heritage.
References
- Sinotte, V.M. et al. (2025). Making yogurt with the ant holobiont uncovers bacteria, acids, and enzymes for food fermentation. iScience, 28, 113595. https://doi.org/10.1016/j.isci.2025.113595
