Prokaryotic Diversity of Biological Soil Crusts in Aridlands of North America

亚利桑那州立大学的Ferran Garcia-Pichel博士和Jean M.Schmidt博士与NASA Ames研究中心的Richard M.Keller博士合作，获得了一项赠款，以对北美生物土壤结皮中存在的微生物多样性进行调查。在植物覆盖受限的干旱土地上，表层土壤中会生长出一层半英寸厚的活微生物，将土壤颗粒聚集在一起，使土壤中含有有机碳和氮。它们被称为生物沙漠结皮，覆盖在植物之间的空间，稳定土壤免受风蚀，防止风沙的形成。目前缺乏关于栖息在这些重要和广泛的表层土壤生境中的微生物种类的知识。在北美沙漠和半沙漠的各种地点，调查人员将着手检测和记录当地的细菌，这些细菌在丰度或新颖性方面具有重要意义。为此，他们将使用现代DNA技术。他们还将尝试在实验室中培养这些微生物。将建立两个储存库。DNA数据库将使其他研究人员未来能够识别结壳微生物。培养的细菌将根据其生态作用和特性进行表征，并将被存放在公共培养库中，以造福于整个科学和生物技术社区。预计这些文件和资料库将构成改善沙漠细菌群落知识的基础，补充我们对沙漠生态的理解，促进健全的牧场管理，并使受严重影响的干旱地区的生物修复努力成为可能。

A grant has been awarded to Drs. Ferran Garcia-Pichel and Jean M. Schmidt at Arizona State University, in collaboration with Dr. Richard M. Keller at NASA Ames Research Center to conduct a survey of the microbial diversity present in biological soil crusts of North America. In arid lands, where plant cover is restricted, a half-inch thick live mantle of microbes develops in the topsoil that traps soil particles together and enriches the soils with organic carbon and nitrogen. Known as biological desert crusts, they cover spaces between plants, stabilizing the soil against wind erosion and preventing formation of blow-sands. There is presently a lack of knowledge regarding the microbial species inhabiting these important and widespread topsoil habitats. In a variety of sites of North American deserts and semi-deserts, the investigators will embark in an effort to detect and document local bacteria important in terms of abundance or novelty. For this, they will use modern DNA technology. They will also attempt to cultivate those microbes in the laboratory. Two repositories will be established. A DNA database will enable the future recognition of crust microbes by other investigators. Cultivated bacteria will be characterized with respect to their ecological role and properties, and will be deposited in public culture collections for the benefit of the scientific and biotechnology community at large. It is expected that these documentation and repositories will constitute the base for improved knowledge of desert bacterial communities, complementing our understanding of desert ecology, facilitating sound rangeland management, and enabling bioremediation attempts in heavily impacted arid areas.