Variation of fungal populations in water-logged ancient sites in the southern Hula valley, Israel

Studies of ancient DNA are increasingly reported, with fungal DNA being fewer. Fungi are important integral organisms in a variety of environmental processes, especially in terrestrial sites, involved in organic soil matter recycling as well as to plant and animal health. Beside, many fungi are used by people for different purposes, such as nutrition, medicine, production of valuable compounds and even are used in mystical ceremonies. Hence, we hypothesized that their presence in ancient sites may reflect on historical climate at the site as well as on human activities. An ongoing archeological excavation in the southern Hula Valley, along the Jordan River, has provided evidence of human activities in ancient time. We have used Next Generation Sequencing analysis to study the soil fungal population of the ancient water-logged site (of 60,000 and 400,000 years old) in comparison with recent soil. Total DNA levels obtained were much lower in the ancient versus contemporary soil levels in the site. Similarly, fungal species richness and abundance in archeological samples were much lower and primarily contained water fungi, such as Cryptomycota species, while the current soil displayed a high variability of functional fungal groups. These results suggest that the water-logged ancient soil is relatively free of live organisms, and that DNA of dead organisms, including fungal DNA, had deteriorated over time.