The focus of this research lies on the detrimental and beneficial effects of bacterial viruses (bacteriophages or phages), as well as on the importance of the phage community (phage virome) in the human gut. The detrimental effects of phages are based on the fact that they are the main cause of fermentation failures, in particular in dairy fermentations. The lactic acid bacteria which are used as starter cultures are targeted and destroyed by the phages. Our research aims to determine the diversity, taxonomy and dynamics of phages in phage-monitoring studies, and to develop strategies for minimizing fermentation failures. One current research project focuses on the assessment of technologically important features of dairy phages, especially the notably high thermal stability of some phages. Hence, these thermo-resistant phages are capable of overcoming the ‘standard’ pasteurization regime hurdle and cause new infections in fermentation tanks. Therefore, non-thermal inactivation methods are currently being investigated as alternatives for heat processing methods.
The beneficial effect of phages is related to their potential use as ‘biocontrol agents’, which is based on the high specificity of phages for their respective bacterial hosts. Phages capable of inactivating either foodborne pathogens or food spoilage microorganisms are investigated i.e. by electron microscopic and molecular biological characterization. This research is especially important against a background of rising numbers of antibiotic-resistant bacteria occurring in the food chain.
A third research focus addresses the human phage virome. Phages are ubiquitous and thus are present in all environments. Accordingly, they also occur in high numbers and diversity in the human gut. Our previous electron microscopic studies confirmed the high biodiversity amongst gastrointestinal bacteriophages. Investigating the effect of the phage virome on the bacterial microbiome in the human gut is a new research area, which will be studied in close collaboration with the food- and gut microbiome research group of the department.