The subsurface microbial loop for nutrient recycling in hydrocarbon-contaminated aquifers

• Applicant: Professor Dr. Rainer Udo Meckenstock, since 6/2021
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management
• Term: from 2020 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 434738594

In polluted aquifers, the highest microbial activity occurs at plume fringes. At these hot spots of biodegradation, the burst in microbial activity leads to a significant increase in biomass concentration but exploits background nutrients over time. In this project, we investigate if the indigenous microbial communities can overcome nutrient-limited conditions at hot spots of biodegradation through the remineralization of nitrogen and phosphorus that are locked up in the dead biomass (necromass). This so-called subsurface microbial loop potentially contributes to establishing a stable microbial ecosystem. We will quantitatively assess the significance of microbial loops for sustained biodegradation of contaminants in groundwater under nutrient-limited conditions. Furthermore, we will quantify the extent of necromass degradation and will evaluate how this alters microbial diversity. We further aim at bringing the single-cell Raman microscopy, and stable isotope probing (SIP) to a next level by developing a high-throughput Raman-activated cell-sorting platform. The activity- or function-based single-cell sorting is based on stable isotope incorporation and micro-fluidics. In combination with molecular analysis, the Raman-activated cell sorting provides quantitative information on the number and phylogenetic identity of the cells involved in the microbial loop and other activities.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Ali Akbari, Ph.D., until 5/2021