LEXEN: Paleobiology of Ancient Salt Formations: Examinations of Primary Crystals for Biological Materials

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This project involves both microbiologists and geologists who will attempt to isolate live microorganisms from extremely old (5 million years and older) salt crystals. The program will develop methods to identify those geological formations most likely to contain crystals with surviving life forms. This project is a continuation and expansion of a successful, exploratory LExEn Project (Paleobiology of Ancient Salt Formations: Examination of Primary Crystals for Trapped Biological Materials, NSF Award # EAR 9714203) during which the investigators isolated the worlds oldest living bacterium (250 million years old) from an ancient sodium chloride crystal. The current project has four main goals. First, to develop new methods and media to isolate, quantify and analyze ancient microbes trapped in NaCl crystals. Second, to improve understanding of life and the paleoenvironment at the time the crystals formed. Third to expand the use of non-contaminating methods for sample recovery. Fourth, to train graduate and undergraduate students for future interdisciplinary work with microbes from extreme environments. This project is based on the hypothesis that small numbers of bacteria, trapped in the stable environment of a salt crystal, can survive for extremely long periods of time. The Principal Investigator's laboratory has been involved in the study of extremely halophilic Archaea associated with salt crystals for over ten years. The Project Director has published ten refereed articles on this topic since 1991. The project will obtain salt crystals that range in age from modern hypersaline environments to Early Miocene (20-24 Ma), Early/Middle Eocene (ca. 50 Ma), Late Permian (ca. 250 Ma), and Late Silurian age (408- 421 Ma). The data produced will describe the state of evolution and the environment in which these crystals originally formed. The investigators will also complete the description of the 250 million year old bacteria they have already isolated from Permian aged crystals.