The origin of sporobiota in freshwater sediment

Due to their long-term stability, endospores and other spore-like structures buried in sediments constitute a natural archive of past environment. Such biological structures may be used as proxies for studying environmental changes and reconstructing ecosystem history. To validate this approach, the autochthonous origin of the endospore-forming community needs to be demonstrated. In this project, the origin of bacterial spores was explored in two alpine lakes located in Grisons, Switzerland (Jöri lakes I and XIII). Microbial community was analyzed from samples representative of the lakes (sediments cores and water column) and of the surrounding environments (soils and river inlets). Samples were collected from the lakes (sediments cores and water column) and from the surrounding environment (soils and river inlets). Both the total community and the sporobiota were analyzed by sequencing 16SrRNA gene amplicons.