PhD candidate in Molecular Microbiology

The biotechnology sector plays a crucial role in improving quality of life worldwide, but many current bioproduction processes rely heavily on sugar-rich feedstocks derived from crops that compete with food production. Developing sustainable alternatives is therefore a major scientific and societal challenge. Photosynthetic cyanobacteria offer a promising solution, as they use light and carbon dioxide to produce sugars, enabling more sustainable production routes.

To address this challenge, the Institute of Biology at Leiden University is seeking a PhD candidate for a project focused on engineering synthetic bacterial partnerships for renewable bioproduction. This PhD project is part of a funded research programme aiming to develop stable synthetic consortia between cyanobacteria and actinomycetes for the sustainable production of bioactive compounds.

Are you eager to explore how synthetic microbial partnerships can transform industrial biotechnology?

We are looking for a creative and highly motivated PhD candidate to study the biology, evolution, and biochemistry of engineered cyanobacteria–actinomycete symbioses. The project integrates microbiology, synthetic biology, and evolutionary approaches, and contributes to the development of sustainable, photosynthesis-driven production platforms for bioactive compounds.

The project builds on recent discoveries that certain cell wall-deficient actinomycetes can internalize intact bacterial cells via an endocytosis-like mechanism, opening the door to creating the first bacterial–bacterial synthetic endosymbiosis. By combining metabolic cross-feeding, genetic interdependencies, and guided laboratory evolution, the PhD candidate will investigate how stable symbiotic interactions can be established, optimized, and maintained over time.

Key tasks

• Design, construct, and maintain synthetic microbial consortia composed of cyanobacteria and actinomycetes for sustainable bioproduction
• Investigate the biological mechanisms underlying bacterial–bacterial symbiosis, including uptake, stability, and metabolic integration
• Characterize phenotypic, physiological, and biochemical properties of synthetic symbioses using microbiological and molecular approaches.
• Communicate research findings through scientific publications and public engagement activities
• Contribute to teaching activities, for example through supervision of BSc and MSc students.

Research at our faculty
The Faculty of Science is a world-class faculty where staff and students work together in a dynamic international environment. It is a faculty where personal and academic development are top priorities. Our people are committed to expand fundamental knowledge by curiosity and to look beyond the borders of their own discipline; their aim is to benefit science, and to make a contribution to addressing the major societal challenges of the future.

The research carried out at the Faculty of Science is very diverse, ranging from mathematics, information science, astronomy, physics, chemistry and bio-pharmaceutical sciences to biology and environmental sciences. The research activities are organized in eight institutes. These institutes offer eight bachelor’s and twelve master’s programs. The faculty has grown strongly in recent years and now has almost 2,800 staff and over 6,000 students. We are located at the heart of Leiden’s Bio Science Park, one of Europe’s biggest science parks, where university and business life come together.

For more information, see www.universiteitleiden.nl/en/science and www.universiteitleiden.nl/en/working-at

Institute of Biology, Leiden University
The research within the Institute of Biology Leiden (IBL) aims to work on the science base of biodiversity and health, which is reflected in our leading principle Harnessing Biodiversity for Health. We perform innovative curiosity-driven research to answer fundamental questions, and solutions-driven research to help solving major societal challenges. The latter include protecting nature’s biodiversity, creating sustainable biotechnology and agriculture, and increasing good health. Our research focuses on four Research Themes: Bioactive Molecules, Host-Microbe Interactions, Development & Disease and Evolution & Biodiversity. IBL offers an exciting, internationally oriented, and inclusive place to work and study. For more information about IBL see: www.universiteitleiden.nl/en/science/biology.

Selection criteria

• Candidates should have an MSc degree with a strong background in microbiology, molecular genetics, microscopy and/or biochemistry and an excellent grade list
• Candidates preferably have experience working with cyanobacteria
• Candidates should have excellent written and spoken English skills and be willing to acquire sufficient proficiency in Dutch
• Candidates are expected to have a critical mindset with the ability to think outside the box.

What we offer
Our goal is to work together to create a transparent and inclusive work environment in which everyone feels welcome and appreciated. Our organisation is always evolving and we need your ideas for improvement and innovation to take us further. We want to devote attention to your personal development.

You can count on an enjoyable job within the socially relevant world of education and research. The University's challenging and international work environment is located just steps away from Leiden’s lively city centre or the bustling city centre of The Hague. We also want to work with you to devote attention to your health and vitality, for example with the fun activities we organise through Healthy University.

We offer a 1-year position with the possibility of extension to 4 years based on performance and following the pay scale P in accordance with the Collective Labour Agreement for Dutch Universities. Salary ranges from € 2.901,- gross per month in the first year to € 3.707,- gross per month in the fourth year based on a full-time position (38 hours).

Leiden University offers an attractive benefits package with additional holiday (8%) and end-of-year bonuses (8.3 %), training and career development and sabbatical leave. Our individual choices model gives you some freedom to assemble your own set of terms and conditions. For international spouses we have set up a dual career programme. Candidates from outside the Netherlands may be eligible for a substantial tax break.

What we find important
Promoting an inclusive community is central to Leiden University’s values and vision. Leiden University aims to be an inclusive community in which all students and staff members feel valued and respected, and are able to develop to their full potential. Diversity in experiences and perspectives enriches our teaching and strengthens our research. High-quality education and research means inclusive education and research.

Want to apply or find out more?
Applications for this vacancy can be submitted via the blue button of our online system. Please ensure that you upload the following additional documents quoting the vacancy number:

• A letter of motivation describing research interests and demonstrating fit with the project (max. 2 pages)
• Curriculum vitae
• Relevant certificates (e.g. degree certificate)
• Contact information for two referees.

Only applications received before 2 February 2026 can be considered.

Enquiries about the position can be made to Prof. Dr. Dennis Claessen (d.claessen@biology.leidenuniv.nl). If you have any questions about the procedure, please contact Christina Kamerman (HR@biology.leidenuniv.nl).

To help us get to know each other better, we follow a number of steps in the application procedure. For more information, see https://www.universiteitleiden.nl/en/working-at/job-application-procedure-and-employment-conditions

• In choosing between candidates, in case of equal suitability, preference will be given to internal candidates, women, the occupationally disabled and employees with a migration background.
• A pre-employment screening (references, diplomas, certificate of good conduct (VOG)) may be part of the selection procedure.
• Acquisition in response to this vacancy is not appreciated. If you nevertheless choose to send us CVs, no rights can be derived from this. #LI-Hybrid