Bacterial Biogeography of Large Rivers in the Mississippi River Basin

生物地理学研究的目标是确定物种在空间和时间上的分布模式和原因。对动植物生物地理学的研究可以追溯到几个世纪前。然而，微生物生物地理学的研究很少，只有通过现代分子技术才能确定微生物的种类组成。了解微生物生物地理学是至关重要的，因为细菌在所有生态系统中都发挥着核心作用，从它们参与食物网到它们促进对营养循环和污染物去除至关重要的化学转化。该项目将描述密西西比河流域大型河流中微生物群落的生物地理学，包括俄亥俄河、密苏里州、阿肯色州以及密西西比河上游和下游。密西西比河等大型河流网络对生物地理研究很有价值，因为每条河流都反映了其不同的流域特征，导致栖息地因素发生显著变化，可能影响微生物组成和生态功能。该项目的一个主要目标是将生境因素与微生物种类组成及其生理功能联系起来，微生物酶在营养循环中具有重要作用。密西西比河消耗了美国41%的水域，但人们对生活在密西西比河大河中的微生物多样性知之甚少。这项研究将为这一巨大的河流网络上细菌组成和生理属性的地理变化的程度、原因和后果提供新的科学理解。这项研究的空间范围很广，跨越不同的流域数百公里。该项目的一个更广泛的方面是其教育宣传，包括与当地高中合作，提供关于河流及其分水岭的教案。该项目还将加强对本科生和研究生的河流科学研究的培训，并在密西西比大学开发一门新的创新课程，在重点关注密西西比河的同时，研究文化、生态、生态系统管理和环境伦理之间的关系。

The goal of the study of biogeography is to determine patterns and causes for the distribution of species in space and time. Studies in plant and animal biogeography date back centuries. However, there are few studies of microbial biogeography, which have been made possible only by modern molecular techniques to determine microbial species composition. Understanding microbial biogeography is essential because of the central roles that bacteria play in all ecosystems, ranging from their involvement in food webs to their facilitation of chemical transformations critical to nutrient cycling and pollutant removal. This project will describe the biogeography of microbial communities in large rivers of the Mississippi River Basin, including the Ohio, Missouri, Arkansas, and the Upper and Lower Mississippi Rivers. Large river networks such as the Mississippi are valuable for biogeographic study because each river reflects its distinct basin characteristics, resulting in pronounced variation in habitat factors that may influence microbial composition and ecological functions. A major objective of this project is to link habitat factors to microbial species composition and their physiological functions, as indicated by the activities of microbial enzymes important in nutrient cycling. The Mississippi River drains 41% of the conterminous United States, but little is known about the diversity of microbes inhabiting its large rivers. This study will provide new scientific understanding regarding the extent, causes, and consequences of geographic variation in composition and physiological attributes of bacteria across this great river network. The range in spatial scales of the research is vast, spanning hundreds of kilometers across different river basins. A broader aspect of this project is its educational outreach, which includes collaboration with local high schools to provide lesson plans on rivers and their watersheds. This project will also enhance training of undergraduate and graduate students in the scientific study of rivers, and develop a new, innovative course at the University of Mississippi that examines the relationships of culture, ecology, ecosystem management, and environmental ethics while focusing on the Mississippi River.