Collaborative Research: Loihi Seamount as an Observatory for the Study of Neutrophilic Iron-Oxidizing Bacteria and the Microbial Iron Cycle

合作研究：洛伊希海山作为研究中性粒细胞铁氧化细菌和微生物铁循环的观测站

• 批准号: 0653265
• 负责人: Katrina Edwards
• 金额: --
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-31 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0653265&HistoricalAwards=false
• 关键词: Collaborative; Research; Loihi; Seamount; Observatory

AbstractThe importance of metals to life has long been appreciated. Iron (Fe) is the fourth most abundant element, and the second most abundant redox-active element in Earth's crust, rendering it the most important environmental metal. In recognition of this, a recent surge in research on microbial Fe redox transformations in the environment has resulted in many exciting discoveries and enhanced appreciation for the importance of these processes (Lovley 2000). Most of these studies, however, have focused on the reductive Fe cycle and organisms such as the Geobacteraceae. This is in part because Fe-oxidizing organisms, particularly those who inhabit circumneutral pH habitats, have been notoriously difficult to culture and study in the lab. However, recent successes on this front have resulted in the isolation of a number of novel chemolithoautotrophic Fe-oxidizing bacteria (FeOB). Studies of these bacteria have revealed a remarkable diversity, both physiologically and phylogenetically. This perhaps should not be surprising given that Fe is the most abundant lithoautotrophic energy source in Earth's crust, but is not in keeping with the present attention given to their study. This project is initiating a microbial observatory for the study of iron-oxidizing bacteria (.FeMO.) at the Hawaiian Seamount, Loihi. The major purpose of the project is to elucidate the full physiological, phylogenetic, and biochemical diversity of this group of prokaryotes. Loihi was selected as the study site because: (1) FeOB have been recognized and studied there previously; (2) Loihi displays a wide-range of FeOB habitats: from hydrothermal fluids to rocks, from low-flow, low-T (10C) seeps to high-flow, high-T (60 C) vents; (3) previous studies provided an excellent geochemical framework on which to base these studies; and (4) Loihi is very accessible, located only 25 miles SW of the big island of Hawaii. The research group represents a cross-section of expertise on FeOB. Principal components of the FeMO project include (1) cultural analysis of FeOB, (2) kinetic studies on Fe-oxidation rates, (3) biochemical studies on the Fe oxidase, and (4) biogeochemical studies on colonization and solid rock utilization by FeOB. Microbial Fe redox transformations are well known to impact environmental and human health, for example in organic contaminant degradation and via sorption of toxic radionucleotides, particularly in terrestrial and coastal marine habitats. In the more poorly studied, oligotrophic deep-sea, chemoautotrophic FeOB have recently been recognized for their potentially important role in production of new biomass carbon. This research is leading to significant advances in the study of FeOB and understanding their environmental activities and capabilities, and would enable more accurate predictions about them in many poorly-accessible habitats. The FeMO PIs are involved heavily in middle and high-school teacher education and enhancement efforts at WHOI. These include participation in existing summer workshops, the development of a new school-year weekend mini-workshop, and the direct involvement of a teacher in the FeMO fieldwork. FeMO participants are also strongly involved with higher education on multiple fronts, including the specific recruitment of female and minority undergraduates from a New England women's college (Smith) for summer internships via the Praxis program.

摘要金属对生命的重要性已被人们赞赏。 铁（Fe）是第四大元素，也是地壳中第二大的氧化还原活性元素，使其成为最重要的环境金属。 为了认识到这一点，最近对环境中微生物FE氧化还原转化的研究激增导致了许多令人兴奋的发现，并增强了人们对这些过程重要性的欣赏（Lovley 2000）。 然而，大多数研究都集中在还原性的Fe周期和生物（例如地球杆菌）上。 这部分是因为臭名昭著的生物，尤其是那些居住的pH栖息地的生物，在实验室中很难进行培养和研究。 然而，这方面的最新成功导致了许多新型的化学可营养性氧化细菌（FEOB）的分离。 对这些细菌的研究在生理和系统发育上都表现出了显着的多样性。 鉴于FE是地球地壳中最丰富的岩性营养能源，但这也许不足为奇，但不符合当前对其研究的关注。 该项目正在启动一个微生物天文台，用于研究夏威夷海峡的Loihi的氧化细菌（.femo。）。该项目的主要目的是阐明这组原核生物的完整生理，系统发育和生化多样性。 洛伊（Loihi）被选为研究地点，因为：（1）FEOB以前已被识别和研究； （2）Loihi显示了广泛的FeoB栖息地：从水热流体到岩石，从低流量，低-T（10C）渗漏到高流量，高-T（60 C）通风孔； （3）先前的研究提供了一个很好的地球化学框架，以基于这些研究； （4）Loihi非常容易进入，位于夏威夷大岛的25英里处。研究小组代表了FEOB的专业知识。 FEMO项目的主要成分包括（1）FEOB的文化分析，（2）Fe氧化速率的动力学研究，（3）Fe氧化酶的生化研究，以及（4）关于定植和FeOB实心岩石利用的生物地球化学研究。微生物FE氧化还原转化众所周知会影响环境和人类健康，例如有机污染物降解以及通过吸附有毒的放射性核苷酸，特别是在陆地和沿海海洋栖息地。 在研究较少，贫营养深海中，化学自动营养的FEOB最近因其在新生物量碳的生产中的潜在重要作用而被认可。 这项研究导致了FEOB的研究和了解其环境活动和能力的重大进展，并可以在许多差的栖息地中对它们进行更准确的预测。 Femo PI大量参与了中学和高中教师的教育以及在Whoi的增强工作。 其中包括参加现有的夏季研讨会，新的学年周末小型工作坊的发展以及教师参与FEMO野外工作的直接参与。 FENO参与者还强烈参与多个方面的高等教育，包括从新英格兰女子学院（Smith）通过Praxis计划招募了新英格兰女子学院（Smith）的女性和少数族裔本科生。