Competence Center Bacteriophages

The bacteriophage competence centre focuses on basic and applied research of bacteriophages (“bacteria eaters”, short: phages) in the food sector. Phages are viruses, that exclusively infect bacteria and therefore have an enormous importance in the processing of a variety of foods. Research conducted in our institute and in collaboration with numerous national and international partners aims at studying the biological and taxonomic diversity of phages in order to gather practice-oriented insight in the disadvantages, but also benefits of phages in food processing. Hereby, the characterization of phages is accomplished by utilizing various microbiological and molecular biological methods, as well as physical techniques.

Our group’s research mainly focuses on the negative and positive aspects of phages in the food sector. The presence of phages in fermentation-based food processes – e.g. the production of cheese from milk – is highly undesired. During fermentation, lactic acid bacteria acidify and thus cause curdling of the milk. A possible contamination with phages, however, can lead to the elimination of these bacteria, causing enormous production losses. To counter those adverse effects, out team analyses the diversity of phages that disrupt fermentations within so-called monitoring studies. Gaining insight into the infection dynamics between bacteria and phages of contaminated batches enables us to develop efficient and directed prevention and defence strategies, in order to conceive a more robust fermentation process.

Another aspect of our research deals with the targeted application of phages against food-borne antibiotic resistant, pathogenic and spoilage bacteria, which highlights the beneficial aspects of these viruses. In virtually every part of the food processing chain, contamination by undesired bacteria can occur, potentially leading to health risks for the consumer or premature spoilage of the product. Here, phages are increasingly being recognized as a safe and natural option to protect product and consumer. In this context, phages can be applied either directly to the food item (biocontrol) or they can be used to disinfect surfaces and equipment in food processing plants (biosanitation). The rationale for the utilisation of phages is their narrow host range: most phages are able to infect only a small number of bacterial species, allowing the elimination of specific undesired bacteria, while the beneficial microbiota (e.g. lactic acid bacteria) remains unaffected. The application of phages in foods has not been established in Germany thus far. Hence, our research aims at gathering novel data and insights into the safety and efficiency of bacteriophages as biocontrol agents.

In order to understand the direct interactions of phages and humans, the competence centre also investigates the presence and role of bacteriophages in the human intestine. Phages are the most abundant biological entities on the planet and their interplay with bacterial hosts massively shapes a plethora of different ecosystems – also the human gut. Recent studies delivered astonishing new insights into the role of nutrition and diet on the composition of the microbiota and their effect on human health. Our group cooperates within several research initiatives in this field using sequencing and metagenomic analyses.