Collection of microorganisms from fermented foods
The collection in brief
Most of the microorganisms in this collection were isolated during the 20th century from milk and fermented dairy products as part of projects aimed at understanding the role of microorganisms in cheesemaking (lactic acid fermentation, formation of flavours and rheological characteristics of cheese dough, hole formation, defects) and at developing starter or adjunct cultures.
Over time, microorganisms isolated from other fermented or non-fermented foods have been incorporated, such as yeasts from grapevine and wine.
The collection contains around 15,000 isolates, mainly lactic acid and propionic acid bacteria (in the form of pure strains or mixtures of strains), but also yeasts, filamentous fungi, and bacteriophages.
Status
For decades or even centuries, Swiss cheesemakers have empirically selected the strains and mixtures of strains best suited to the production of high-quality cheeses. As a result, since 2019, the strains and strain mixtures isolated from Swiss dairy products have been the joint property of Agroscope (Swiss Confederation) and the Swiss dairy and cheese industry. Agroscope is responsible for their maintenance, as well as for the research, development, and production of new fermentation cultures, which are marketed by a limited company (Liebefeld Kulturen SA, https://www.liebefeld-kulturen.ch/). The rest of the collection has no special status, and the exchange of biological material is governed by the rules set out in the Nagoya Protocol.
Applications
Historically, the collection has mainly acted as a reservoir of strains for cheese research (understanding the mechanisms at work during milk fermentation and cheese maturation), as well as for the development of starter and adjunct cultures for the Swiss cheese industry. Recently, the development of protective cultures against undesirable or pathogenic species has provided a new outlet for the strains in the collection. Similarly, the new market for fermented plant products promises new applications for the strains. The collection is constantly growing, with new isolates continually being obtained from various matrices.
Maintenance
The isolates are stored in frozen and freeze-dried form (Fig. 2). Backup stocks are kept at several Agroscope sites.
Information on isolates is referenced in an internal database. An online tool (OpenGenomeBrowser) developed in collaboration with the University of Bern makes genomes available and provides tools for analysing them.
