Fertilization of Salt Marsh Ecosystems: Using Molecular Techniques to Evaluate the Effects of Nitrogen Enrichment on Sediment Microbial Communities

由于沿海地区水域对人民和经济的重要性，这些水域的营养富集日益引起社会关注。 该项目的目标是了解来自陆地的营养物质的增加如何改变盐沼中氮处理细菌的数量和类型。 有两个主要的科学目标。 第一，一种新的、快速的、高分辨率的技术来测序选定的细菌基因？DNA标记法？将进行测试，看看它是否适用于盐沼沉积物。 其次，对氮循环的重要组成部分细菌基因进行具体分析，以确定微生物群落是否会因两年的氮肥施肥而发生显着变化。 人类对沿海沃茨的影响正在改变沼泽和河口，影响它们为社会提供的服务，例如娱乐区和具有重要商业价值的鱼类和贝类的育苗场。 盐沼在河流和地下沃茨到达河口之前就将人类来源的营养物质从沃茨中清除，以这种方式帮助防止营养物质超载或富营养化。 这些清洁活动是由沉积物中的细菌介导的。 尽管它们的重要性，这些沉积物中的细菌，以及人类引起的细菌群落的变化，知之甚少。 该项目将提供关于有前途的新技术和细菌因人类活动而发生变化的方式的信息。

Nutrient enrichment of coastal-zone waters is of increasing societal concern due to the importance of these waters to people and economies. The goal of this project is to understand how increased amounts of nutrients from land change the numbers and types of nitrogen-processing bacteria in salt marshes. There are two primary scientific objectives. First, a new, rapid, high-resolution technique for sequencing selected bacterial genes ? the DNA tag method ? will be tested to see if it works in salt-marsh sediments. Second, specific analyses of bacterial genes that are a vital part of the nitrogen cycle will be quantified to determine if microbial communities change significantly in response to two years of fertilization with nitrogen. Human impacts on coastal waters are altering marshes and estuaries and affecting the services they provide to society, such as areas for recreation and as nursery grounds for commercially important fish and shellfish. Salt marshes cleanse waters of human-derived nutrients before rivers and groundwaters reach estuaries, and in this way help prevent nutrient overload or eutrophication. These cleansing activities are mediated by bacteria in the sediments. Despite their importance, bacteria in these sediments, and human-induced changes in bacterial communities, are little known. This project will provide information on promising new techniques and on ways bacteria change as a result of human activities.