Collaborative Research: Comprehensive Chemical Characterization of Marine Dissolved Organic Matter using Efficient Isolation Coupled to Advanced Analytical Techniques

溶解有机物(DOM)是地球上最大的活性碳库之一，在海洋和全球生物地球化学过程中发挥着重要作用。确定DOM的详细组成和结构提供了无与伦比的回报，因为它们的信息丰富代表了一套独特的生物地球化学示踪剂，能够为了解其母水域的起源和运输过程中这些水域内发生的成岩变化提供重要的见解。最近的分析突破有可能将海洋DOM的主要部分纳入我们的分析窗口，从而极大地促进了对DOM“分子信息”的阅读。此外，使用反渗透结合电渗析(RO/ED)分离DOM的能力也有了很大的改进，现在可以分离高达95%的海洋DOM，而以前的技术只有10%-40%。在这项研究中，来自老道明大学的一名新的研究人员将领导一个包括佐治亚理工学院在内的团队，该团队将把改进的海洋DOM分离与超高分辨率FT-ICR MS和先进的核磁共振光谱的无与伦比的能力相结合，以获得对海洋DOM的组成和控制其组成的生物地球化学过程的重大新见解。这项拟议研究的主要目标是：(1)描述主导海洋DOM池特别是深海DOM池的生物难降解DOM的特征；(2)描述在上升流区新产生的DOM以及在低营养、亚热带环流表层水中积累的半生物可生物和光漂白的DOM；以及(3)将RO/ED分离的DOM与原始样品以及用超滤和固相萃取(例如XAD和C18)分离的DOM进行比较。在更广泛的影响方面，这项研究将为未来的海洋和全球生物地球化学研究奠定基础，在这些研究中，这些先进技术可用于追踪DOM的各种来源，沿着其成岩和运输的不同路径，一直到其出口点、微生物吸收或矿化。此外，PIS将为海洋生物地球化学界提供急需的前兆参考材料。拟议的研究将支持对外开放大学一名新的助理研究教授和三名博士生。与世界卫生组织、麻省理工学院和热点网站的研究人员的合作关系将促进基于实地的合作研究。将酌情设立一个专门的项目网站，并通过公众和新闻媒体互动，促进公众宣传和信息传播。

Dissolved organic matter (DOM) plays major roles in oceanic and global biogeochemical processes as it is one of the Earth's largest active carbon pools. Determining the detailed composition and structure of DOM offers unparalleled rewards as their informational richness represents a unique set of biogeochemical tracers capable of providing important insights into the origins of their parent waters and the diagenetic alterations that have occurred within those waters during transport. Recent analytical breakthroughs have the potential to bring a major fraction of marine DOM within our analytical window, thus greatly facilitating the reading of DOM's "molecular messages". In addition, there has been promising improvement in the ability to isolate DOM using reverse osmosis coupled with electrodialysis (RO/ED) that can now isolate up to 95% of marine DOM compared to ~10-40% for previous techniques. In this research, a new investigator from Old Dominion University will lead a team that also includes Georgia Institute of Technology that will combine improved isolation of marine DOM with the unparalleled power of ultra-high resolution FT-ICR MS and advanced NMR spectroscopy to gain major new insights into the composition of marine DOM and the biogeochemical processes controlling its composition. The main goals of this proposed study are to: (1) characterize bio-refractory DOM that dominates the marine DOM pool especially in the deep sea; (2) characterize newly produced DOM in an upwelling region and the semi-biolabile and photobleached DOM that accumulates in oligotrophic, subtropical gyre surface waters; and (3) compare RO/ED isolated DOM to the original sample and to DOM isolated using ultrafiltration and solid-phase extraction (e.g., XAD and C18). In terms of broader impacts, this research will lay the foundations for future oceanic and global biogeochemical studies where these advanced techniques can be used to trace compounds or component classes of DOM from their multifarious sources, along their various paths of diagenesis and transport, to their points of export, microbial uptake or mineralization. In addition, the PIs will provide critically needed precursory reference material for the marine biogeochemical community. The proposed study will support a new Assistant Research Professor at ODU and three doctoral students. Collaborative ties with investigators from WHOI, MIT and the HOT site will foster cooperative field-based research. Public outreach and information dissemination will be facilitated by creation of a dedicated project website and through public and news media interactions, as appropriate.