Fungi in terrestrial environments are known to play a key role in the cycling of both carbon and nitrogen. In contrast, the role of fungi in marine nitrogen cycling has remained underexplored and often neglected. Marine fungi potentially play a critical and yet unrecognized role in nitrogen cycling such as nitrous oxide (N2O) production, as well as lignocellulose degradation in estuarine and coastal systems. We combine cultivation-based and culture-independent methods to study the functional and taxonomic diversity of marine fungi in the context of biogeochemical cycles.
Nitrogen is a limiting element for biological productivity and has a strong influence on cycles of many other elements, including carbon, sulfur, and phosphorus. The transformation of different forms of nitrogen is primarily mediated by microorganisms, either for nitrogen assimilation or to gain energy. Anoxic and hypoxic environments are hot spots for dissimilatory reactions that account for most of the loss of biologically available nitrogen. We combine stable isotope-based techniques and ‘omics methods to investigate the microbial transformation of nitrogen in sediments and oxygen minimum zones.
Coastlines are the most densely populated regions on earth and have been directly impacted by pollutions and climate change. It is known that functions of estuarine and coastal ecosystems have been altered in response to anthropogenic influences. Nevertheless, it remains uncertain how the microbiomes in these ecosystems evolve over long time scales and how such changes in turn influence the health of estuarine and coastal ecosystems. We conduct both lab and field experiments to examine the feedback between environmental changes and microbial communities.