SGER: New Scales of Measuring Organic Carbon Diagenesis in Marine Sediments

摘要OCE-0129555来自南加州大学的首席研究员将利用两项尖端技术对底栖有机碳循环进行调查。 最初，PI将利用基因工程细菌（希瓦氏菌属）创建氧气分布图。其可被改性以使用氧或氧化锰或电子受体的任何组合来进行碳氧化。 使用这些细菌将允许PI构建氧分布，控制有机底物类型/分布、氧化剂可用性/分布和细菌群落丰度/分布。 本研究的目的是提供一个直接的关系，在沉积物中观察到的溶质配置文件和进行氧化还原反应，以产生一个给定的配置文件所需的细菌的类型和丰度。 此外，PI还将与来自德国的一位科学家合作，使用剖面X射线荧光扫描仪，以2-3毫米的间隔或3-6年的分辨率测定南加州和墨西哥低氧地点层状沉积物中的Fe、Ca、Mn和Ti。 本研究的目的是获得高分辨率图像的变化固相铁，锰，钛和碳酸盐作为时间的函数，以确定成岩锋和解释海洋生产力的变化。

AbstractOCE-0129555A principal investigator from the University of Southern California will take advantage of two cutting-edge technologies for an investigation of benthic organic carbon cycling. Initially, the PI will create oxygen profiles utilizing genetically engineered bacteria (Shewanella sp.) which can be modified to perform carbon oxidation using either oxygen, or manganese oxide, or any combination of electron acceptors. Using these bacteria will allow the PI to construct oxygen profiles with control over organic substrate type/distribution, oxidant availability/distribution and bacterial community abundance/distribution. The goal of this research is to provide a direct relationship between solute profiles observed in sediments and the type and abundance of bacteria needed to carry out the redox reactions to yield a given profile. In addition, the PI also will use a profiling X-ray fluorescence scanner in collaboration with a scientist from Germany, to determine Fe, Ca, Mn and Ti in laminated sediments from low-oxygen-sites off Southern California and Mexico at 2-3 mm intervals or 3-6 years of resolution. The objective of this study is to obtain high resolution images of changes in solid phase Fe, Mn and Ti and carbonate as a function of time to identify diagenetic fronts and interpret changes in ocean productivity.