Interdisciplinary PhD projects

PhD students in BioSC Core Groups have the opportunity to apply for interdisciplinary small-scale projects with a six-month duration across different BioSC partner locations and research areas. There are one or two calls for proposals per year.

Projects 2025:

Photo: Applied Microbiology, RWTH Aachen Photo: Applied Microbiology, RWTH Aachen

The project Food4Root aims to contribute to sustainable practices in agriculture by addressing a key environmental challenge of the sector: The overuse and inefficiency of conventional fertilizers. Traditionally used fertilizers are often applied in large quantities and across entire fields, without considering the crop-specific nutrient demands. This leads to a considerable accumulation of excess nutrients in the soil, promoting environmental pollution and nutrient loss, ultimately deteriorating the overall soil health- and quality. Food4Root strives to develop a targeted nutrient-delivery system by designing biodegradable gel-beads that slowly release fertilizing compounds to the plant. This ensures that nutrients are only deployed in areas that can be reached by plants, improving the soil quality and promoting continuous plant growth. The innovative fertilizer beads are based on natural biopolymers produced by microorganisms: Polyphosphate, which provides phosphorus, and polyglutamate, a nitrogen-containing compound. These materials are encapsulated into gel matrices, ensuring that the nutrients are only released from their polymeric form upon microbial activity in the root zone. Addition of iron sulfate and calcium chloride was shown to significantly improve the stability of the gel beads, while also embedding essential micronutrients to further support plant growth. Following a successful production scale-up from the beaker to the bioreactor, the influence of these biodegradable beads on plant development is now being investigated in a controlled environment. With this, Food4Root supports the transition towards greener farming practices and contributes to continuous efforts in ensuring global food security while preventing environmental pollution. 

Photo: Illustration of the interdisciplinary collaboration in this project. Forschungszentrum Jülich Photo: Illustration of the interdisciplinary collaboration in this project. Forschungszentrum Jülich

The HAIPSs3D project developed an ultra-low-cost microfluidic live-cell imaging platform by combining a 3D-printed Open Flexure Microscope with AI-based image analysis. The full system cost ~300 EUR and supported automated imaging of 16 cultivation chambers for live-cell experiments with Corynebacterium glutamicum. Using CellposeSAM and acia-workflows, we achieved automated segmentation and quantitative single-cell metrics, including growth rates of 0.64–0.77 h⁻¹ and the expected bi-modal single-cell-size distribution. Focus loss during stage motion and slow xy-movement limited temporal resolution, however the quantitative readouts were robust enough to compile the results in a manuscript in preparation for submission (see appendix). In parallel, we developed tools for controlled phototoxicity studies by cloning four photosensitizers into inducible expression vectors for C. glutamicum and Pseudomonas putida, achieving robust, tunable expression. Batch-culture viability assays (propidium iodide) showed strong photosensitizer- and strain-dependent differences in phototoxicity, demonstrating precise control of light-induced cellular damage. Due to time constraints, we could not yet combine the low-cost imaging platform with photosensitizer-based phototoxicity experiments in a single integrated study. However, the achievements in this project establish an excellent foundation to implement this combined approach in the near future.