Collaborative Research: Carbon and Electron Acceptor Cycling in Lake and Estuarine Sediments During Early Diogenesis

沉积物中有机物的分解是一个重要的过程，它将营养物质返还给上面的水，并控制世界海洋和湖泊中埋藏的碳量。生活在沉积物中的细菌除利用分子氧外，还利用各种氧化剂降解有机物。这些替代氧化剂包括硫酸盐、硝酸盐以及铁和锰的氧化物。现在很清楚，这些替代氧化剂在沉积物-水界面附近被密集地循环利用，而且直接利用氧气进行的分解量比以前认为的要小。这对我们模拟水生生态系统和其他沉积物过程（如污染物的释放）的碳收支具有重要意义。PI将1)检查控制替代氧化剂使用的因素，2)确定有机物的年龄和类型如何影响氧化剂的再循环，以及3)确定替代氧化剂的存在是否会增加有机物的总分解。

9528017 Giblin Collaborative: Carbon and Electron Acceptor Cycling in Lake and Estuarine Sediments The decomposition of organic matter in sediments is an important process which returns nutrients to the overlying water and controls the amount of carbon buried in the worlds oceans and lakes. Bacteria living in sediments degrade organic matter using a variety of oxidants in addition to molecular oxygen. These alternative oxidants include sulfate, nitrate, and the oxides of iron and manganese. It is now clear that these alternative oxidants are intensively recycled near the sediment-water interface and that the amount of decomposition being directly carried out using oxygen is smaller than previously believed. This has important implications for our ability to model the carbon budgets of aquatic ecosystems and other sediment processes, such as the release of contaminants. The PI's will 1) examine the factors controlling the use of alternative oxidants, 2) determine how the age and type of organic matter influences oxidant recycling, and 3) determine whether the presence of alternative oxidants increases total organic matter decomposition.