Mites used for aging in German and French Cheese Factories are actually the same species ― Revealed by Japanese research group

In Europe, mites have been used as a traditional cheese ripening method for centuries. The mites used are in the Acaridae family, frequently appearing in French literature since the 18th century, as a representative example of tiny living creatures. It turns out that the mites used in three distantly separated cheese factories in Germany, France, and Italy are the same species.

The finding was discovered by a research group led by Professor Satoshi Shimano of the Science Research Center and Faculty of Intercultural Communication, Hosei University, Professor Nobuhiro Shimizu of the Faculty of Bioenvironmental Science, Kyoto University of Advanced Sciences, Associate Professor Shimpei Hiruta of The Mt. Fuji Institute for Nature and Biology, Showa University, and others. The findings were published in the journal Experimental and Applied Acarology.

Are mites unique to cheese factories in the same way yeast in breweries becomes more unique across generations? To answer this question, the group collected mites directly from the aging rooms of three cheese factories, Milbenkase (Milben = mites, Kase = cheese) in Germany, Mimolette and Artisou in France, and cheese from specialty stores in Paris and Japan. When mites were collected directly from Mimolette and Laguiole, each with long histories, only one species of cheese mite, Tyrolichus casei, was found.

Using a massively parallel DNA sequencer, researchers analyzed the genetic structure of the cheese mites from each of the cheese aging rooms, and despite the factories being 500 kilometers apart, they found no genetic geographical separation in the results.

Cheeses that use mites for ripening are said to have a unique flavor. The research group used gas chromatography-mass spectrometry to detect neral, which provides a lemon-like flavor, in Tyrolichus casei. It is unknown if mites secrete this as a pheromone or for anti-fungal purposes. However, no mite-derived neral was detected in Artisou, one of the three kinds of cheese from the ripening rooms the researchers visited. Due to this, the mites do not appear to contribute any direct flavoring to this type of cheese.