Cycling of Labile Intermediates at the Oxic/Anoxic Interface

90%以上的有机碳埋藏在海洋沉积物中 每年都在缺氧的沉积物中发现， 沉积物-水界面的厘米。 此外该 缺氧条件下分解的有机碳量 据估计，条件在约10%和 几乎100%的量在好氧环境中矿化 厌氧分解在 确定的数量和化学成分的 最终被掩埋的物质。 然而， 缺氧条件对特定有机物分解速率的影响 对化合物的了解很少。 一个环境， 可以研究流动率变化的相对重要性 恒定和变化的生产率的浓度 有机化合物是好氧/缺氧过渡区。 的 好氧/缺氧界面是一个分层的微生物区域， 人口和快速变化的属性。 本研究 将是第一个关注影响人类行为的过程 发酵中间体的分布和周转 （氢、乙酸盐、丙酸盐、低分子量胺） 和DOC附近的好氧/缺氧界面，因此， 提供关于水柱碳的地点的宝贵信息 在这样的系统中再生。 结果还将提供 了解不稳定化合物的周转率如何在 氧化还原梯度，以及周转率的变化 或生产率是导致集中的原因 马克西姆 与微生物数据相比， 还将提供有关角色的定性信息 不同的微生物种群在碳中的作用 周转

More than 90% of the organic carbon buried in marine sediments each year is found in sediments which are anoxic within a few centimeters of the sediment-water interface. In addition, the amount of organic carbon which is remineralized under anoxic conditions has been estimated to be between about 10% and almost 100% of the amount remineralized in oxic environments and anaerobic decomposition plays an important role in determining the quantity and chemical composition of the material which is ultimately buried. However, the effect of anoxic conditions on the decomposition rate of specific organic compounds is poorly understood. One environment in which we can study the relative importance of changes in turnover rate constant and changes in production rate to concentrations of organic compounds is the oxic/anoxic transition zone. The oxic/anoxic interface is a region of stratified microbiological populations, and of rapidly changing properties. This study will be one of the first to focus on the processes affecting the distribution and turnover of fermentation intermediates (hydrogen, acetate, propionate, low molecular weight amines) and of DOC near the oxic/anoxic interface, and will thus provide valuable information on sites of water column carbon regeneration in such systems. The results also will provide insights on how turnover rates of labile compounds vary within redox gradients, and whether variations in the turnover rates or in production rates are responsible for concentration maxima. When compared with microbiological data, the results will also provide qualitative information about the roles played by the different microbial populations in carbon turnover.