Structural and Functional Diversity of Endolithic Microbial Communities in Arid Deserts

微生物对环境的健康和功能至关重要，但就不同种类的数量及其在环境中的功能而言，它们的多样性在很大程度上仍未得到探索。在非常干燥的沙漠中，当水稀缺，太阳辐射强烈时，岩石内部为微生物生命提供了最后的避难所。通过一系列实验室实验和实地测量，这项研究将描绘出世界各地沙漠岩石中微生物群落的多样性和活动特征。这个项目将使我们了解在沙漠化发生时可能发现的强健微生物的多样性，并有助于确定一个地区在长期沙漠化后的恢复潜力。通过增加我们对沙漠微生物多样性、进化和生态学的认识，我们将更多地了解我们的生物圈，以及如何更好地节约资源和保护环境。采用大规模的跨学科方法，该项目将确定控制干旱环境中内生（生活在岩石中的）微生物群落的遗传、结构和功能组成的因素。本研究将使用高通量基因测序和最先进的显微镜方法对居住在内生生态系统中的微生物的生物多样性进行调查。此外，研究人员将利用培养和单细胞基因组学来确定这些生态系统中光合作用生物的遗传多样性和分子适应性。本研究的结果将对来自几个大陆的内生生态系统中微生物的生物多样性进行全面调查，确定当地环境（即岩石类型和当地气候）或全球环境（即生物地理）是否对群落组成产生强烈影响，并确定这些生态系统中光养生物的分子适应性及其与环境变量的关系。参与项目的博士后1人，研究生1人，本科生数人。巴尔的摩市的一所公立高中将参与以世界各地干旱沙漠的地质学和生物学以及荒漠化对人类福祉的影响为中心的活动。一名高中生将参加美国的野外考察。公众将通过一个国际公民科学项目参与其中。

Microbes are essential for the health and functioning of the environment, yet their diversity, in terms of the number of different kinds and their functions in the environment, remains largely unexplored. In very dry desert, when water is scarce and solar radiation high, the inside of rocks provides the last refuge for microbial life. Using an array of laboratory experiments and field measurements, this research will characterize the diversity and activities of microbial communities found inside rocks in deserts around the world. This project will inform us on the diversity of robust microbes that we might expect to find when desertification takes place and help determine the recovery potential of an area after long periods of desertification. By increasing our knowledge of the diversity, evolution, and ecology of desert microbes, we will learn more about our biosphere and how to better conserve resources and protect the environment.Using a large-scale interdisciplinary approach, this project will identify the factors that govern the genetic, structural, and functional composition of endolithic (living in rock) microbial communities from arid environments. This research will provide a survey of the biodiversity of microorganisms inhabiting endolithic ecosystems using high-throughput gene sequencing and state-of-the-art microscopy methods. In addition, the researchers will determine the genetic diversity and molecular adaptations of photosynthesizing organisms from these ecosystems using culturing and single-cell genomics. Results from this study will provide a comprehensive survey of the biodiversity of microorganisms inhabiting endolithic ecosystems from several continents, determine whether the local environment, (i.e. rock type and local climate) or the global environment (i.e. biogeography) strongly impact community composition, and identify molecular adaptations of phototrophs from these ecosystems and how they relate to environmental variables. One postdoctoral fellow, a graduate student, and several undergraduate students will participate in this project. A public high school in Baltimore City will be involved in activities centered around the geology and biology of arid deserts around the world and the impact of desertification on human well-being. One high school student will participate in a field expedition in the US. The general public will be engaged via an international citizen science project.