The Group of Plant Nutrition of the Department of Environmental Systems Science for the Project: Crop production in hydroponics using recycled nutrients and microbial consortia invites applications to apply for
PhD position in the MELiSSA (Micro-Ecological Life Support System Alternative) program of the European Space Agency

The acronym MELiSSA means 'Micro Ecological Life Support System Alternative'. It refers to a space research program aiming to develop an artificial ecosystem for regenerative life support systems for long-term space missions ( At the same time it is an excellent model for addressing terrestrial challenges such as urban agriculture using mineral nutrients from societal wastes, and overall to close nutrient cycles between food production and consumers. The objective of the PhD project is to maximize food crop production in hydroponics based on nitrified urine by minimizing risks of salinization and of nutrient deficiency at the same time as producing food of high nutritional quality. Food crop production will be explored using a sequence of crops and substrates based on nitrified urine, either alone or amended with fertilizers produced from bio-wastes. Microbial consortia will be used to stabilize the nutrient solutions and to optimize nutrient availability. The plant response in term of shoot and root growth, yield and nutritional quality of edible parts, and nutrient use efficiency will be investigated. The microbial consortia will be developed in collaboration with the partners at the University of Ghent. The results will permit to optimize the food production based on nutrients recovered in the MELiSSA loop. The project will provide new insights on closing nutrient cycles. It will involve most advanced technologies to treat human excreta and to design microbial consortia to optimize plant nutrition in closed systems.

The PhD project will be undertaken in the Group of Plant Nutrition, Research Station Lindau-Eschikon, ETH Zürich (, and includes a one-year stay at the University of Ghent, Department of Biochemical and Microbial Technology and Department of Plant Production.

We are looking for a PhD candidate who is highly motivated and with the necessary skills to plan and carry out tasks independently. The candidate will also be required to spend one year at the University of Ghent, and travel to workshops/conferences, work in an interdisciplinary team, and publish research findings in internationally peer-reviewed journals.

Applicants must have received a university degree or equivalent (MSc or similar) that entitles them to undertake doctoral studies at the ETH Zürich ( A background in one of the following or related disciplines is needed: microbiology, plant physiology, chemistry, biotechnology, bioengineering or agricultural plant sciences. It is desirable the candidate has experience in plant cultures, microbiology, and/or molecular methods. It is required that the candidate has an advanced knowledge of written and spoken English.

The PhD candidate will be supervised by Dr Astrid Oberson and Professor Dr Emmanuel Frossard from the Group of Plant Nutrition (ETH Zürich), and by Professor Nico Boon and Professor Danny Geelen from the University of Ghent. The project includes collaboration with the Aquatic Research Institute Eawag in Dübendorf, Switzerland, and with the Paul-Scherrer Institute in Villigen, Switzerland. The candidate’s salary will be in accordance with ETH/SNSF regulations.

We look forward to receiving your application including a letter of motivation, CV, B.Sc. and M.Sc. transcripts, electronic copies of the B.Sc./M.Sc. thesis and/or publications (if available), and names and addresses of references. Please note that we exclusively accept applications submitted through our online application portal. Applications via email or postal services will not be considered. Application deadline is February 28th 2018 (or until a suitable candidate is found).

For further information, please contact Dr Astrid Oberson at astrid.oberson[at] (no applications) or visit our website