The potential of German wetland ecosystems – an investigation of the biodiversity and secondary metabolite production of Basidiomycota with a focus on their antibiofilm properties

• Applicant: Dr. Hedda Schrey
• Subject Area: Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems ; Ecology and Biodiversity of Plants and Ecosystems
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 534769897

According to recent molecular ecology studies, there are millions of underexplored basidiomycetes – many of them have a fascinating ecology. To defend their ecological niche against other competitors, they are equipped with a biosynthetic machinery to form unique and biological active secondary metabolites. Two of these underexplored habitats for innovative chemistry are the German wetlands and the dung of herbivorous mammals. Studies conducted on coprophilous fungi found that the surrounded biodiversity stimulates the production of numerous antimicrobial compounds. Although wetlands are often characterized by a wide variety of organisms, embedded in a complex community, only a few studies are known about their secondary metabolism – and much less about their production of secondary metabolites with effects on biofilms. On the other hand, the rapid global spread of antimicrobial resistance has currently become a major challenge. Biofilms are very common in medicine but highly resistant to conventional antibiotics. New therapeutic strategies and novel antimicrobial agents are urgently needed to tackle this problem. Therefore, the following proposal will focus on fungal organisms, which are exposed to biofilm populations in their natural environment. Aim is to evaluate whether saprothrophic basidiomycetes from both, the German wetlands and herbivorous dung have a special potential for the production of secondary metabolites with selective antibiofilm properties. Therefore, secondary metabolites from fungal cultures (submers/emers) without any cytotoxicity against mammalian cell lines will be isolated and evaluated for their inhibitory and disruptive effects on biofilm formation and preformed biofilms of different pathogens, such as Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Candida auris. Herein, the mode of action of isolated antibiofilm candidates will be analyzed via complementary methodologies (e.g. crystal violet assay, confocal microscopy, scanning electron microscopy, reporter gene assays, synergistic testing). Furthermore, the capacity of organisms to produce active secondary metabolites will be compared from the wetlands, as an example for nutrient-poor habitats, and the dung, as a nutrient-rich environment. With this, the project wants to shed more light on the chemical ecology of the fungal organisms from these outstanding habitats. Through mapping and deposition of the organisms in official strain collections, the proposed project will give an important contribution to inventory and conservation of the fungal diversity from wetlands, which are highly threatened due to the changing climatic conditions. Additionally, a touring exhibition for the science-minded public is planned at the end of the project period, which aims to highlight the potential of fungi, both in the context of wetland ecosystems and antimicrobial drug research.

• DFG Programme: Research Grants