The GEOMAR Helmholtz Centre for Ocean Research Kiel in Germany is inviting applications for a fully funded Doctoral Researcher (m/f/d) position in Marine Biogeochemistry. This 36-month PhD project focuses on the study of metalloenzymes in the nutrient metabolism of marine phytoplankton, starting June 1, 2026 (negotiable).
Research Background and Project Scope
Marine phytoplankton are microscopic photosynthetic organisms that drive global biogeochemical cycles, sustain marine food webs, and regulate atmospheric carbon dioxide. However, nutrient imbalances—particularly phosphorus limitation—are increasingly threatening ocean productivity. Under global change scenarios, phosphorus scarcity in marine ecosystems is projected to worsen.
To survive under nutrient stress, phytoplankton rely on specialized metal-dependent enzymes (metalloenzymes) to access alternative nutrients. These pathways require metal cofactors like manganese or other trace metals. This doctoral project, funded by the German Research Foundation (DFG), is embedded within the Emmy Noether research group “Metalloenzymes,” led by Dr. Viktoria Steck, investigating the project: Coupled Phosphorus and Manganese Controls on Ocean Ecosystem Fertility.
Core Research Objectives
The doctoral candidate will combine laboratory biochemistry, marine microbiology, and oceanographic observations to address:
- How phytoplankton biochemically adapt to phosphorus limitation.
- The role of metal cofactors in enzymatic nutrient acquisition.
- How trace metal availability and nutrient stress interact in the ocean.
- Scaling molecular-level findings to predict ecosystem-level carbon cycling.
Key Responsibilities
During the PhD program, the candidate will:
- Conduct sterile culturing and growth experiments of marine phytoplankton under controlled nutrient limitations.
- Recombinantly express, purify, and characterize metalloenzymes through biochemical assays.
- Apply advanced proteomics, metaproteomics, and metallomics workflows under trace-metal clean conditions.
- Participate in oceanographic research cruises and field sampling campaigns.
- Publish findings in peer-reviewed scientific journals and present at conferences.
Qualifications Required
Required:
- M.Sc. in Biochemistry, Microbiology, Oceanography, Biogeochemistry, Genomics, or a related field.
- Hands-on laboratory experience in microbial culture, protein purification, molecular cloning, or ‘omics workflows.
- Data handling skills in Excel, R, or Python.
- Excellent English communication skills.
Preferred:
- Prior experience in trace-metal biogeochemistry or mass spectrometry.
- Willingness to participate in sea-going expeditions.
Salary and Benefits
The position is funded for 36 months, structured at 75% E13 TVöD-Bund. GEOMAR provides a supportive environment with flexible hours, mobile working options, 30 vacation days, and structured training via the FYORD doctoral program in Kiel Marine Sciences.
Application Process
Applications must be submitted online by March 15, 2026. Use the official application portal: Apply Online – GEOMAR Job Portal.
For scientific questions, contact Dr. Viktoria Steck at vsteck@geomar.de. For administrative inquiries, email bewerbung@geomar.de and reference the keyword “metalloenzymes”. Visit the GEOMAR Website for more details.
Frequently Asked Questions
Is the position open to international applicants?
Yes. GEOMAR is an international research institution and English is the official working language.
Will I go to sea as part of my doctoral studies?
Yes. The project includes opportunities to participate in oceanographic field cruises to collect environmental samples.
What salary scale is followed?
The position is funded at 75% TVöD E13, following the standard collective agreement for the public service in Germany.