Collaborative Research: Examination of Diverse Anaerobic Methane Oxidizing Archaea and Associated Syntrophic Relationships Using High Resolution Molecular and Isotopic Methods

合作研究：使用高分辨率分子和同位素方法检查多种厌氧甲烷氧化古菌及其相关的互养关系

• 批准号: 0348596
• 负责人: Victoria Orphan
• 金额: $ 25万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0348596&HistoricalAwards=false
• 关键词: Collaborative; Research; Examination; Diverse; Anaerobic

The characterization of methane-consuming microorganisms and the factors that control their activity on the micro scale is important in our understanding the biogeochemical cycling of methane on a global scale. The world's oceans are one of the largest sources of methane, yet only a fraction of this greenhouse gas is released into the atmosphere because it is consumed by microorganisms in anoxic marine sediments. Cross-disciplinary investigations have recently shown that the process of anaerobic oxidation of methane (AOM) is mediated by novel uncultured Archaea, the ANME-1 and ANME-2, in syntrophic association with sulfate-reducing bacteria. This project is studying methanotrophic Archaea (including ANME-1 and ANME-2) from methane seep environments and pure cultures of Methanosarcina acetivorans and Methanococcoides methylutens (close cultured relatives of the ANME-2) using a series of experiments combining fine scale molecular RNA-based and isotopic analyses. The objectives are aimed at identifying the microbes responsible for and understanding the process of AOM through three broad areas of research. The goals of this research are: (1) to characterize the diversity and metabolic versatility of microorganisms responsible for AOM by expanding and refining the current database on the natural carbon isotopic composition of cells in methane-rich sediments, (2) to develop constraining thermodynamic models of AOM by identifying where active cells reside in natural ANME-2/Desulfosarcina consortia, (3) to elucidate metabolic aspects of AOM by constraining intermediates of the process and by identifying possible vitamins and co-factors involved. These cross-disciplinary studies are hypothesis-driven investigations aimed at understanding the underlying mechanisms and syntrophic relationships of methane-oxidizing microbial cells and consortia through combined cell-specific molecular and isotopic analyses. This research will generate a unique high-resolution isotopic data set that will serve as a basis for modeling the thermodynamics of AOM as well as assist in defining the complex interactions between microorganisms involved in the cycling of methane. This approach is highly complementary to ongoing studies of anaerobic methane oxidation by geochemists and microbiologists and provides a unique perspective to assist in elucidating this globally important, but poorly characterized process.The education and outreach program will expand interest in geomicrobiology at the grade school, undergraduate, and graduate level. This project will provide team-oriented graduate education in microbial geobiology, engaging undergraduates through existing programs aimed at increasing diversity in the sciences, and building on existing infrastructure aimed at K-12 teacher education. Specifically, the PIs are contributing to the annual PSU teacher's workshop by teaching a session on the important role microbes play in regulating climate on Earth. Through connections with Dr. Benita Bell from Bennett College, a historically Black women's college in Greensborough, North Carolina, the PIs are introducing underrepresented students to the field of geobiology through a workshop during Space Science Week at Bennett. At the graduate level, the project will provide educational opportunities to graduate students at Penn State and Caltech.

甲烷消耗微生物的特性和控制其活动的因素在微观尺度上是重要的，在我们的理解在全球范围内的甲烷地球化学循环。世界海洋是甲烷的最大来源之一，但只有一小部分这种温室气体被释放到大气中，因为它被缺氧海洋沉积物中的微生物消耗。跨学科的研究表明，甲烷厌氧氧化过程是由新的未培养的厌氧微生物ANME-1和ANME-2介导的，它们与硫酸盐还原菌互养。 本项目通过一系列实验，结合精细的分子RNA和同位素分析，对甲烷渗漏环境中的嗜甲烷菌（包括ANME-1和ANME-2）以及产乙酸甲烷八叠球菌和甲基丁香甲烷球菌（ANME-2的近缘培养物）的纯培养物进行了研究。其目的是通过三个广泛的研究领域来确定负责AOM的微生物并了解AOM的过程。本研究的目标是：（1）通过扩展和改进关于富含甲烷的沉积物中细胞的天然碳同位素组成的现有数据库，来表征负责AOM的微生物的多样性和代谢多样性，（2）通过识别活性细胞在天然ANME-2/脱硫八叠球菌聚生体中的位置，来开发AOM的约束热力学模型，（3）通过限制AOM过程的中间体和鉴定可能涉及的维生素和辅因子来阐明AOM的代谢方面。 这些跨学科的研究是假设驱动的调查，旨在通过结合细胞特异性分子和同位素分析，了解甲烷氧化微生物细胞和财团的潜在机制和互养关系。 这项研究将产生一个独特的高分辨率同位素数据集，作为AOM热力学建模的基础，并有助于定义参与甲烷循环的微生物之间的复杂相互作用。 这种方法是高度互补的厌氧甲烷氧化的地球化学家和微生物学家正在进行的研究，并提供了一个独特的视角，以协助阐明这一全球重要的，但不好的特点process.The教育和推广计划将扩大在小学，本科生和研究生水平的兴趣在地球微生物学。 该项目将提供微生物地球生物学领域以团队为导向的研究生教育，通过旨在增加科学多样性的现有项目吸引本科生，并在针对K-12教师教育的现有基础设施的基础上进行建设。具体来说，PI通过讲授微生物在调节地球气候方面的重要作用，为PSU年度教师研讨会做出贡献。通过与班尼特学院（北卡罗来纳州格林斯伯勒一所历史悠久的黑人女子学院）的贝尼塔·贝尔博士的联系，PI正在通过班尼特空间科学周期间的一个讲习班向代表性不足的学生介绍地球生物学领域。 在研究生阶段，该项目将为宾夕法尼亚州立大学和加州理工学院的研究生提供教育机会。