Collaborative Research: The Impact of Pelagibacter on DOM Composition Under Light and Dark Conditions

合作研究：Pelagibacter 在光照和黑暗条件下对 DOM 组成的影响

• 批准号: 0751897
• 负责人: Elizabeth Kujawinski
• 金额: $ 30.37万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-15 至 2012-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0751897&HistoricalAwards=false
• 关键词: Collaborative; Research; Impact; Pelagibacter; DOM; Collaborative; Research; Impact; Pelagibacter; DOM

Heterotrophic bacterial metabolism and photochemical degradation are two of the primary transformative mechanisms for dissolved organic matter (DOM) in the marine environment. In this research, scientists from Woods Hole Oceanographic Institution, Oregon State University and University of Maryland will attack both issues by comparing use of individual compounds of DOM affected by light or by a single bacterial species. Pelagibacter ubique is a ubiquitous marine bacterial species and can represent up to 25% of the heterotrophic bacterial population in the ocean. Although P. ubique has been isolated into laboratory culture and its genome has been sequenced, the growth requirements of this important marine bacterium are not well constrained, although nutrient limitation of P. ubique growth is not alleviated by the addition of inorganic or organic supplements. The scientists will build on their preliminary work that indicates that P. ubique incorporates and produces different compounds when grown under light conditions than under dark conditions, which is surprising since P. ubique exhibits no growth differences under light and dark conditions, despite the presence of a proteorhodopsin proton pump. The researchers will investigate the impact of photochemistry on the suite of compounds incorporated and produced by P. ubique during growth experiments, determining the molecular-level composition of DOM by Fourier Transform Ion Cyclotron Resonance Mass Spectroscopy (FTICR-MS) and its optical characteristics before and after incubation with P. ubique. Identification of growth substrates of P. ubique in the presence and absence of light will be an important step forward in constraining possible substrates for heterotrophic activity in marine systems.An important component of this work will be the continued development of an analytical framework for FTICR-MS data. First, they will further develop work with internal standards and novel spectral alignment algorithms. Second, they will enhance existing automated analytical tools to include ancillary information regarding compound structure and composition such as polarity predictions from liquid chromatography and fragmentation spectra from MS/MS experiments. Their goal is to provide a data analysis pipeline that includes automated calibration, spectral alignment, robust spectral comparisons and elemental formula assignments. Among the broader impacts of this research is the development of an analytical framework for robust and routine examination of FT-ICR MS data that is critical for the applications of this technique to biogeochemistry. The researchers will train graduate students at WHOI, UMD and OSU in FTICR MS and will provide travel funds to graduate students from other institutions in order to disseminate their approach to the broader geosciences community.

杂营的细菌代谢和光化学降解是海洋环境中溶解有机物（DOM）的两种主要变换机制。 在这项研究中，俄勒冈州立大学和马里兰州大学的伍兹霍尔海洋学机构的科学家将通过比较使用光或单一细菌物种的DOM的单个化合物来攻击这两个问题。 Pelagibacter Ubique是一种普遍存在的海洋细菌物种，可以代表海洋中多达25％的异养细菌种群。 尽管已将假单胞菌已分离为实验室培养物，并且已经对其基因组进行了测序，但这种重要的海洋细菌的生长需求却没有很好地限制，尽管并不能通过添加无机或有机补充剂来减轻富比克生长的营养限制。 科学家将基于他们的初步工作，表明在光条件下生长的情况下，P. ubique在黑暗条件下生长并产生不同的化合物，这是令人惊讶的，因为尽管存在蛋白质蛋白质蛋白质质子泵，但在光和黑暗的条件下，P. ubique在光和黑暗条件下却没有生长差异。研究人员将研究光化学对生长实验期间P. ubique掺入和生产的化合物套件的影响，从而通过傅立叶转化离子转化循环共振质谱法（FTICR-MS）及其在与P. Ubique孵育之前和之后确定DOM的分子水平组成。 在存在和不存在光线的情况下，在限制海洋系统中异养活性的可能底物的重要一步中，在存在和不存在光线的情况下鉴定生长底物。首先，他们将通过内部标准和新型光谱比对算法进一步开发工作。其次，它们将增强现有的自动分析工具，以包括有关复合结构和组成的辅助信息，例如液相色谱的极性预测以及MS/MS实验的碎片化光谱。他们的目标是提供一个数据分析管道，其中包括自动校准，光谱比对，可靠的光谱比较和元素公式分配。 这项研究的更广泛影响之一是开发用于对FT-ICR MS数据进行稳健和常规检查的分析框架，这对于该技术在生物地球化学上的应用至关重要。 研究人员将在FTICR MS的Whhi，UMD和OSU培训研究生，并将向其他机构的研究生提供旅行资金，以便将他们的方法传播到更广泛的地球科学社区。