P352 Molds and yeasts on the beach: environmental factors influencing distribution of fungi along european shores

POSTER SESSION 3, SEPTEMBER 23, 2022, 12:30 PM - 1:30 PM: OBJECTIVES: The present study employed data collected during the Mycosands survey to investigate the environmental factors influencing yeasts and molds distribution along European shores by applying a species distribution modeling approach. METHODS: Occurrence data were compared to climatic datasets (temperature, precipitation, and solar radiation), soil datasets (chemical and physical properties), and water datasets (temperature, salinity, and chlorophyll concentration) downloaded from web databases. All dataset layers were edited and formatted by QGIS software and analyses were performed by MaxEnt software. RESULTS: The distribution maps inferred comparing occurrence data on shores for Aspergillus spp., Aspergillus fumigatus, A. flavus, A. niger, Fusarium spp., dematiaceous fungi, and considering all molds, to climatic datasets showed the highest probability of presence along Eastern and South-Central Mediterranean coasts, whereas comparison of water occurrence data to water features identified a high suitability along Eastern Mediterranean coasts, Gulf of Lion, Southern coasts of Spain, and Southern and Central Atlantic coast of Portugal, Southern Atlantic coast of France, Netherlands coasts, the mouth of Danube, coasts of the Ireland sea, and Kuri Lagoon in Lithuania. The main variables contributing to the models were minimum temperatures in winter, water temperature during spring, and chlorophyll concentration. The comparison with soil datasets showed a high tolerance of soils with a high concentration of CaCO3 and basic pH. Nitrogen concentration was tolerated at values below 1 g/kg and phosphorus concentration at values <20 mg/kg and >40 mg/kg. In addition, the model identified a high tolerance to soils rich in nickel. The same analyses were performed for the following groups of occurrence data: Candida spp., Rhodotorula spp., and all yeasts. Results showed the highest probability of presence on shores located along the coasts of Eastern Mediterranean Sea, Southern-Central Mediterranean Sea, Northern Adriatic Sea coasts, Kuri Lagoon, and Northern European coasts from France to Denmark. In waters, high suitability areas were located along the coasts of Northern Black Sea, Northern Adriatic Sea, coasts of Ireland Sea, Western Atlantic coast of France, and the Northern European coasts from France to western Denmark. The most relevant variables contributing to the model were minimum temperatures during winter and water chlorophyll concentration. The comparison with soil features showed similar results to those obtained for molds, except a high tolerance for soils rich in cadmium. CONCLUSIONS: All together our results suggest a different probability of distribution of yeasts and molds along European shores. Yeasts seem to tolerate low temperatures better during winter than molds and this reflects a higher suitability for the Northern European coasts. This difference is more evident considering suitability in waters. Both distributions of molds and yeasts are influenced by basic soil pH, probably because acidic soils are more favorable to bacterial growth. Soils with high nitrogen concentrations are not suitable for fungal growth, which, in contrast, are optimal for plant growth, favored by this environment. Finally, molds show affinity with soil rich in nickel and yeasts with soils rich in cadmium resulting in a distribution mainly at the mouths of European rivers or lagoons, where these metals accumulate in river sediments.