Directly quantifying the isotopic fractionation associated with the key enzymes in microbial sulfate reduction

直接量化与微生物硫酸盐还原中关键酶相关的同位素分级分离

• 批准号: 1225980
• 负责人: David Johnston
• 金额: $ 23.92万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1225980&HistoricalAwards=false
• 关键词: Directly; quantifying; isotopic; fractionation; associated

The microbial lifestyle of sulfate reduction is central to the oxidation of organic matter both in the Modern and throughout Earth?s history. This linkage to the carbon cycle, and in turn climate, is commonly inferred through sulfur isotope studies, which are themselves informed by experiments with extant bacteria that perform this process. At its core, however, bacteria are driven by a suite of enzymes, or catalysts, that conduct much of the critical chemistry. In this proposal, investigators look to place the first direct isotopic constraints on the two key enzymatic steps within this metabolism: dissimilatory sulfite reductase [DsrAB/C] and APS oxido-reductase [APSr]. This data will allow for a more mechanistic understanding of cellular fractionation processes, which will then sharpen our capacity to read environmental records.This research project will be conducted in collaboration with Dr. Ines Pereira of the Instituto De Technologia Quimica E Biologica, ITQB, Portugal, who will provide the biochemistry expertise necessary for the project. A Harvard graduate student will travel between the Pereira and Johnston's labs, acquiring valuable interdisciplinary training in isotope geochemistry and biochemistry. Travel costs for the international component of this research have been provided by the NSF Office of International Science and Engineering.

硫酸盐还原的微生物生活方式是现代和整个地球有机物氧化的核心。年代的历史。这种与碳循环和气候的联系通常是通过硫同位素研究推断出来的，而硫同位素研究本身是通过对现存细菌进行这一过程的实验得出的。然而，在其核心，细菌是由一套酶或催化剂驱动的，这些酶或催化剂进行了许多关键的化学反应。在这项提议中，研究人员希望对这一代谢过程中的两个关键酶步骤：异化亚硫酸盐还原酶（DsrAB/C）和APS氧化还原酶（APSr）进行第一次直接的同位素限制。这些数据将允许对细胞分馏过程有更机械的理解，这将提高我们读取环境记录的能力。该研究项目将与葡萄牙ITQB Quimica E bi研究所的Ines Pereira博士合作进行，他将为该项目提供必要的生物化学专业知识。一名哈佛研究生将在佩雷拉和约翰斯顿的实验室之间穿梭，在同位素地球化学和生物化学方面获得宝贵的跨学科培训。本次研究国际部分的旅费由美国国家科学基金会国际科学与工程办公室提供。