Keywords:
Chemotaxis; Bacterial behaviour; Microfluidics; Carbon cycling; Synergistic interactions
Description: Chemotaxis is a key behaviour in the marine environment, enabling bacteria to locate and exploit nutrient hotspots such as marine particles and the phycosphere, thereby shaping large-scale nutrient cycling in the ocean. Recent work from our lab revealed the first example of multiple phytoplankton metabolites synergistically influencing bacterial chemotaxis: the ubiquitous organosulfur compound DMSP enhances bacterial attraction to the polysaccharide laminarin by supplying methyl groups to the chemotactic machinery. Since DMSP and other methyl-group-containing molecules are widespread in the ocean, this mechanism is likely to extend to diverse bacteria and chemical cues.
In this project, the student will use microfluidics and microscopy to investigate bacterial chemotactic responses towards ecologically relevant compounds and how these responses are modulated by methyl-group-containing molecules. Understanding how methylation regulates chemotaxis will provide new insights into nutrient turnover and its consequences for ocean ecosystem functioning. We are seeking a motivated student with a background in microbiology and an interest in working at the interface of marine microbial ecology and environmental engineering.
Skills you will learn:
- Microfluidics assays to quantify and characterize bacterial chemotaxis (fabrication and lab experiments)
- Standard microbiology cell culture techniques
- Light microscopy
- Flow cytometry for bacterial population identification and cell counts
- Data analysis for characterization and quantification of bacterial motile behaviour (Python; Matlab; R)
Goal: This project aims to characterize how widespread the effect of methyl-group–containing molecules is in enhancing bacterial chemotaxis towards ecologically relevant compounds in the ocean.
Project start: January 2026 or by arrangement
Location: Environmental Microfluidics Laboratory, IfU, D-BAUG (ETH Zurich, Hönggerberg campus)
Project type: This project can be adapted for a Master’s thesis or a Master’s project.
Contact details: Valerio Anelli – vanelli@ethz.ch