PhD Position in Tropical Geomicrobiology: Modern and Ancient Microbial Drivers of Biogeochemical Cycling

100%, Zurich, fixed-term

We seek a highly motivated PhD candidate for a multidisciplinary project across two groups: (i) The Sustainable Agroecosystems (SAE) group in the Department of Environmental Systems Science at ETHZ is dedicated to bringing healthy food from fields to tables around the world for generations to come. (ii) The Surface Earth Evolution (SEE) group in the Department of Earth and Planetary Sciences at ETHZ is committed to investigating the processes that drive global climate change over human to geologic timescales. Combined, our work intersects traditional Earth- and environmental- science fields to holistically study the drivers and impacts of changing climate and land use. We effectively integrate field-based sample collection and monitoring with lab-based biogeochemical measurements.

Project background

This position is part of the SNSF-funded project ’Constraining tropical wetland greenhouse gas production today and through time: insights from Tumba-Ngiri-Maindombe, Democratic Republic of Congo (LacMai)’, which aims to mechanistically constrain the climatic and anthropogenic controls on greenhouse-gas (i.e., carbon dioxide, methane, and nitrous oxide) emissions in Tumba-Ngiri-Maindombe, a severely understudied region that houses the world’s largest tropical wetland. To do so, we will sample greenhouse gases, peatland soils, and lake sediments, and we will analyze these using isotopes, biomarkers, and DNA-based methods.

This PhD candidate will lead the microbial component of this interdisciplinary project. Using state-of-the-art molecular techniques, you will identify the microbial drivers and metabolic capacity in tropical lake sediments and reconstruct how they have evolved in response to climatic shifts over the past 12,000 years (i.e., the Holocene).

Job description

• Perform fieldwork: Participate in sampling expeditions to DR Congo to collect high-resolution, pristine sediment records from Lake Mai Ndombe and surrounding peatlands, ensuring appropriate preservation for molecular and biological analyses
• Contemporary microbial profiling: Perform DNA extraction, qPCR, and ribosomal metabarcoding on surface sediments. Quantify key functional marker genes (e.g. mcrA, pmoA, nosZ) and identify extant microbial drivers of modern carbon and nitrogen cycles
• Ancient DNA analysis: Execute specialized DNA extraction from deep sediment cores under rigorous contamination controls. Utilize shotgun metagenomics to reconstruct the structural and functional adaptation of microbial communities to paleo-environmental shifts
• Integrative bioinformatics: Process complex sequencing datasets using advanced computational pipelines. Perform taxonomic profiling and metabolic reconstruction to link microbial drivers with shifting environmental parameters from sediment records
• Communicate findings: Attend international conferences and workshops and write scientific papers

This position is integral to the research team, which includes 2 PhD candidates, 2 senior scientists, and several technicians across two research groups. You will therefore lead these tasks but will be supported by all involved researchers. This multidisciplinary team offers the opportunity to learn, develop, and apply scientific skills beyond traditional geomicrobiology!

Profile

• Education: MSc degree in (geo)microbiology, molecular ecology, or a related field
• Wet-lab experience: Solid experience in molecular biology techniques (e.g. DNA extraction, PCR and qPCR, sequencing library preparation). Prior experience working in an ancient DNA facility or a similarly controlled ’clean lab’ is a strong asset
• Computational skills: Experience with analyzing amplicon and metagenomic data is highly desirable
• Remote fieldwork: Willingness to conduct fieldwork in a remote tropical environment
• Communication: Proficiency in written and spoken English and ability to communicate in a cross-cultural environment
• Knowledge of French is a plus (for fieldwork)
• Personal attributes: Ability to work independently with flexibility, critical thinking, and a willingness to learn new skills!

Workplace

We offer

• A fully funded 4-year PhD position embedded in the SAE group
• The opportunity to work in a unique, understudied region of high scientific and climatic value
• Excellent, inclusive working conditions, a strong international network, and an internationally competitive salary (paid according to ETH standards )

Working, teaching and research at ETH Zurich

We value diversity and sustainability

In line with our values , ETH Zurich encourages an inclusive culture. We promote equality of opportunity, value diversity and nurture a working and learning environment in which the rights and dignity of all our staff and students are respected. Visit our Equal Opportunities and Diversity website to find out how we ensure a fair and open environment that allows everyone to grow and flourish. Sustainability is a core value for us - we are consistently working towards a climate-neutral future .

Curious? So are we.

We look forward to receiving your online application until 15.03.2026 with the documents:

• Curriculum Vitae including educational history, any publications, awards, etc.
• BSc and MSc transcripts (in English or German)
• Motivation letter (~2 pages) describing your interests and relevant experience
• Contact details of two references

Shortlisted applicants will be invited for an interview by 31.03.2026. Start date will ideally be June-July 2026. Questions regarding the position should be directed to Dr. Martin Hartmann, martin.hartmann@ usys.ethz.ch .

Please note that we exclusively accept applications submitted through our online application portal. Applications via email or postal services will not be considered.

We would like to point out that the pre-selection is carried out by the responsible recruiters and not by artificial intelligence.

Apply online now

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