What is Espress'EAU?

Water is an essential resource that we regularly use for drinking, cooking and food processing. Hence, it is important to ensure that it is safe for consumption. EspressEAU serves as an analysis of general water quality. We aimed to create a safe, low-cost, and easy-to-use system that can enable on-site testing of water at home or in small communities. We hypothesized that genetically engineered yeast could be used as biosentinels by hijacking the yeast stress response pathway using either deletion strains or fluorescent reporter strains that are sensitive to water contaminants. These biosentinels are grown in a DIY system with temperature control, stirring, and two optical detectors for fluorescence and density, allowing us to monitor growth and fluorescence of the yeast, and thus detect the presence of contaminants in the water sample. We hope our project will facilitate frequent water testing of local water sources.


Water is essential to human beings. Monitoring its quality is therefore of high priority. Espress’EAU allows assessing the water quality and ensure that it is safe for consumption.

Wet Lab

We created genetically engineered yeast strains, deletion and fluorescent strains, that are sensitive to the presence of contaminants in water.


Our biosentinel strains are therefore incorporated in a device created from scratch, combining optical density and fluorescence detectors to monitor yeast growth and fluorescence.

Human Practices

Our system was tailored in order to tackle current and local problems that several actors helped us identify throughout the entire process of designing our project.

Special thanks to our sponsors!

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@EPFL iGEM 2020