Das Projekt "Entwicklung und Bewertung neuer Verfahren und Ansaetze zur Feststellung von Bakterien unter dem Meeresboden der Tiefsee und deren Wechselwirkung mit Prozessen in der Geosphaere DEEP BUG" wird vom Umweltbundesamt gefördert und von Max-Planck-Institut für marine Mikrobiologie durchgeführt. Objective: Development and assessment of new techniques and approaches for detecting deep sub-seafloor bacteria and their interaction with geosphere processes (DEEPBUG). Problems to be solved: Marine sediments cover 70 per cent of the Earth's surface and contain the largest global reservoir of organic carbon. Surprisingly, high bacterial populations are present to at least hundreds of metres depth (deepest current sample 842 m, oldest 14 mya) in these sediments. These bacteria are not just surviving, they are thriving in the extreme conditions at these depths; they have high diversity and are well adapted to life in the subsurface. Bacterial biomass in these sediments represent ca.10 per cent of the total surface biomass and the sub-seafloor biosphere is a substantial new habitat on Earth. Bacteria probably exist even deeper where they are fuelled by geosphere processes. However, existing microbiological techniques are inadequate for deeper investigation. This project will develop new techniques and approaches for deep biosphere research and these will be tested and refined in deep sediment simulation experiments and by application to future Ocean Drilling Program (ODP) Legs. These procedures will then be used to explore this biosphere's coupling to the geosphere and explore even deeper the frontiers of life in the sub-seafloor. Scientific objectives and approach: This project involves an interdisciplinary group of microbiologists and organic geochemists to develop methods and approaches to explore the deep biosphere in sub-seafloor sediments. New core handling techniques will be developed for deeper more consolidated sediments. Existing methods used to quantify total bacterial populations (direct microscopy), their rates of activity (using 35S and 14C labelled compounds) and to identify active bacterial populations (incorporation of 13C labelled substrates into bacterial PLFA biomarkers and/or 16S-rRNA) will be optimised for the study of the deep sub-surface. Modified or new methods will be applied to deep sediment samples taken on future ODP legs. Temperature limits for bacterial activities will be determined in thermal gradient experiments. This will enable a greater understanding of how this ecosystem functions at the biosphere:geosphere interface. In addition novel deep bacteria of potential biotechnological application will be isolated. The latest molecular genetic techniques (DGGE) will be applied to these unique samples to obtain a detailed description of their diversity. Molecular probes will also be developed to rapidly identify and isolate novel organisms in mixed cultures and deep sediments. Prime Contractor: University of Bistrol, Department of Earth Sciences, Research Centre for Environmental and Geophysical Flows; Bistrol, Clifton.