PhD student to investigate the inactivation of viruses by microbial activity

The Laboratory of Environmental Virology (LEV) in the Environmental Engineering Institute, EPFL, is seeking a PhD student to investigate the inactivation of viruses by microbial activity.

Our group is interested in the fate of human viruses in the environment. Viruses enter natural water bodies via the discharge of wastewater, from where they can be transmitted to new hosts and cause a range of diseases from diarrhea to hepatitis and meningitis. The virus ability to encounter and infect a new host depends in part on its environmental persistence. Yet, our understanding of the environmental fate of human viruses is far from complete. Our lab has previously found that lakewater bacterial communities and isolates inactivate human viral pathogens. We have seen a correlation between viral inactivation and microbial diversity and expression of some proteolytic enzymes. However, the ecological underpinnings and molecular mechanisms behind viral inactivation by these microbes remain poorly understood.

The PhD project aims to characterize the role of bacterial metabolism in virus inactivation and elucidate some of the molecular mechanisms related to this process. We will use chemostat experiments to cultivate lakewater microbial communities to compare metabolism and viral inactivation rates under different nutrient conditions and identify extracellular metabolic processes (enzymes and small molecules) that impact virus stability. For this work, we will combine -omics and biochemical approaches.

The PhD project aims to characterize the role of bacterial metabolism in virus inactivation and elucidate some of the molecular mechanisms related to this process. We will use chemostat experiments to cultivate lakewater microbial communities to compare metabolism and viral inactivation rates under different nutrient conditions and identify extracellular metabolic processes (enzymes and small molecules) that impact virus stability. For this work, we will combine -omics and biochemical approaches.

The successful applicant will closely collaborate with a Postdoc and a second PhD student, as well as with scientists from the EPFL-RIVER lab and a USDA Research team. English proficiency (spoken and written) is essential.

We are looking for candidates with a Master’s degree in environmental sciences, microbiology, biochemistry, chemistry or a related field. Prior experience in microbiology and/or -omics approaches is beneficial.

We offer a fully funded 4-year position in stimulating international research environment, good research infrastructures and resources, a competitive salary, and the opportunity to live and work along the shores of beautiful Lake Geneva.

The position will start January of 2026. Applications will be accepted until the position is filled. PhD applicants must be accepted by the EPFL Doctoral School in order to pursue a PhD. For more information, please see https://www.epfl.ch/education/phd/edce-civil-and-environmental-engineering/.

For further information about this lab and project, consult https://www.epfl.ch/labs/lev/ or contact Prof. Tamar Kohn. For additional information about obtaining a PhD at EPFL, please consult http://phd.epfl.ch/prospective.
To apply, please send the following documents :

• a letter of motivation
• your CV
• the name and contact information of at least two references
• 1 page summary of your Master thesis
• transcripts of the grades of your Bachelor and Master degrees

Application deadline: [31/10/2025]

Contract Start Date: 01/01/2026

Activity Rate Min: 100.00

Activity Rate Max: 100.00

Contract Type: CDD

Duration: 4 years

Reference: 1720