Understanding microbial manganese-oxidizing communities and physiological mechanisms in metal oxide-rich hydrothermal sediments using a metagenomic and metatranscriptomic approach

使用宏基因组和宏转录组方法了解富含金属氧化物热液沉积物中的微生物锰氧化群落和生理机制

• 批准号: 1129553
• 负责人: Bradley Tebo
• 金额: $ 79.93万
• 依托单位: Oregon Health & Science University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1129553&HistoricalAwards=false
• 关键词: Understanding; microbial; manganese; oxidizing; communities

Hydrothermal systems are important sources of dissolved Mn to the oceans. Upon oxidation of Mn(II), Mn(III,IV) oxides are deposited at the sea floor as crusts, nodules and sediments both near and far from the sources. Microbial activity has long been recognized as being important to the fate of Mn in these hydrothermal systems, yet we know very little about the organisms that catalyze Mn oxidation, the mechanisms by which Mn is oxidized or the physiological function that Mn oxidation serves. The overarching goals of this project are to reveal the organisms and mechanism(s) underlying Mn(II) oxidation, to evaluate whether hydrothermal Mn oxidizers may obtain energy from Mn oxidation, and test whether thermophilic Mn oxidizers exist. Specifically, the project will: 1) evaluate whether we can identify certain genomic sequences that correlate to the presence/concentration of Mn oxides (and hence Mn(II)- oxidizing bacteria) by comparing the metagenomes of ferromanganese (containing both Mn and Fe oxides) microbial mats with ferruginous (Fe oxide only) mats from Lau Basin and Loihi Seamount; 2) use peptide probes bound to magnetic particles for selectively binding and capturing Mn oxide particles and characterizing the particles using phylogenetic and functional gene (PCR and FISH) and transcriptomic analysis; 3) assess the main pathways of carbon fixation in ferromanganese microbial mats as compared to ferruginous mats as a possible indicator of Mn-based auto/mixotrophy using genomic approaches and substrate stimulated (e.g., addition of Mn(II)) CO2 fixation measurements and stable isotope probing (SIP) genomic analysis; and 4) isolate and characterize Mn(II)-oxidizing bacteria and determine whether thermophilic Mn oxidizers exist.Intellectual meritThe results of this research will increase our understanding of Mn(II) oxidation in hydrothermal sediments, identify microorganisms that are the environmentally relevant Mn oxidizers and begin to address the long standing question of whether Mn auto/mixotrophy exists using approaches not based on the biases associated with cultivation. Ultimately this information is critical to our understanding of biogeochemical cycles (Mn oxidation and Mn oxides impact many other elemental cycles, including carbon, sulfur, and heavy metals) and the natural attenuation of toxic metal and organic compounds; this may lead to improved technologies for environmental remediation. Because Mn oxides are believed to be an analog to the ancestral Mn centers in photosystem II, this research may also lend new insights into ancient biogeochemistry occurring before the Great Oxidation Event.Broader impactsThe project will provide support and training for one Ph.D. student and one postdoctoral researcher, and will contribute to the education of undergraduate and highly qualified high school students through independent research projects and mentorships. They will participate in a geoscience education program targeting the education of 6-12 grade Alaskan Native Americans. In addition, this project will contribute to a training program targeted to middle school teachers that highlights the connections between chemistry, biology, and geology in the environment. The results of the work will be broadly disseminated through presentations, publications, and the World Wide Web.

水热系统是向海洋溶解的MN的重要来源。 Mn（II）氧化后，Mn（III，IV）氧化物被沉积在海底，因为外壳，结节和沉积物均接近和远离来源。在这些热液系统中，长期以来，微生物活性对MN的命运很重要，但是我们对催化Mn氧化的生物，MN被氧化或MN氧化的生理功能的机制知之甚少。该项目的总体目标是揭示MN（II）氧化的生物体和机制，以评估水热Mn氧化剂是否可以从MN氧化中获取能量，并测试是否存在嗜热MN氧化剂。具体而言，该项目将：1）评估我们是否可以确定某些与Mn氧化物的存在/浓度相关的基因组序列（以及Mn（II） - 氧化细菌），通过将Ferromanganese（同时包含MN和Fe氧化物）的微生物（MN和Fe氧化物）与富氧化物（Fe氧化物）的元素进行比较，通过将lauui sat和lauui sats和lauui sats进行比较来进行比较。 2）使用与磁性颗粒结合的肽探针进行选择性结合并捕获Mn氧化物颗粒，并使用系统发育和功能基因（PCR和FISH）（PCR和FISH）以及转录组分析来表征颗粒； 3）与铁质垫相比，使用基因组方法和底物刺激（例如，MN（II）添加了稳定的固定测量值和稳定的同位素探针（SIP（SIP）基因分析），评估基于MN的自身/混合体的碳固定量的主要途径是基于MN的自身/混合体的指标；和4）分离株和表征Mn（II）氧化细菌并确定是否存在嗜热Mn氧化剂。智能优先。优点这项研究的结果将增加我们对水热沉积物中Mn（II）氧化的理解，并根据环境与长期相关的MN氧化剂的氧化方法，并确定与MN氧化物相关的问题，该氧化是否可以与MN氧化的相关问题。与种植相关的偏见。最终，这些信息对于我们对生物地球化学周期的理解至关重要（MN氧化和MN氧化物影响许多其他元素周期，包括碳，硫和重金属），以及有毒金属和有机化合物的自然衰减；这可能会导致改进的环境修复技术。由于Mn氧化物被认为是光系统II中祖先MN中心的类似物，因此这项研究还可能为大型氧化事件发生之前发生的古代生物地球化学提供新的见解。Boader的影响。BoaderImplations Project该项目将为一位博士提供支持和培训。学生和一名博士后研究员将通过独立的研究项目和指导来为本科和高素质的高中学生的教育做出贡献。他们将参加针对6至12年级的阿拉斯加原住民教育的地球科学教育计划。此外，该项目将有助于针对中学教师的培训计划，该计划突出了环境中化学，生物学和地质学之间的联系。这项工作的结果将通过演示，出版物和万维网进行广泛传播。