PIRE: Toward a holistic and global understanding of hot spring ecosystems: A US-China based international collaboration

尽管自20世纪60年代和70年代布洛克在黄石国家公园的开创性工作以来取得了巨大进展，但我们对高温下生态过程的理解仍然有限。该PIRE项目建立在美国和中国地质生物学家之间现有的合作基础上，以组建一个大型国际团队，专注于中国最大的温泉综合体-云南省腾冲地热田地热源池内的微生物多样性，地理学和生态系统水平功能。该项目的长期目标是对地热系统的地球生物学形成一种整体和全球的观点，以补充和借鉴对黄石国家公园等其他地热地点的生命的了解。此外，美国学生和科学家将有机会体验中国西南地区的生物、地质和文化多样性，并发展长期的国际合作。高温生态系统（73°C）的研究是生物学的前沿，因为支持这些生态系统的能量来自化学不平衡，而不是光。该PIRE团队的专业知识使其能够测试中心假设，即地理上不同的温泉系统拥有遗传上不同的微生物群落，具有相似的碳（C）和氮（N）循环功能。这一假设将被测试集中在散装水和沉积物微生物群落的源池的六个温泉，代表三个主要的物理化学类。该项目的研究目标是：1）通过广泛的地球化学分析和热力学模拟，将温泉定义为微生物的物理化学栖息地; 2）通过16 S rRNA基因片段的深度测序，全群落宏基因组学和荧光原位杂交，从系统发育和基因含量的角度来确定微生物群落结构; 3）通过DNA和脂质稳定同位素探测，以及碳和氢天然丰度稳定同位素测量，测量碳循环过程的速率和碳循环中关键参与者的痕量同化碳; 4）应用一套全面的氮循环过程速率测量，结合N循环基因和转录本的深度测序，将过程与N循环中的关键参与者联系起来;（5）对栽培生物的基因组进行测序，以揭示其在生物地球化学循环中的可能作用，特别是C-和N-循环，以及基因组尺度上的微生物特有性。结合仔细的网站特性，直接测量微生物的活动，和基因组的方法将导致一个前所未有的，综合了解这个系统。当与美国正在进行的类似工作相结合时，该团队将获得一个详细的窗口，了解地球化学和微生物地理学在控制微生物群落结构和功能方面的相对作用。该项目的教育目标包括：1）吸引美国研究生和本科生、内华达州高中科学教师、早期职业研究人员、国际地质微生物学界，和公众参与全球科学研究和国际合作; 2）激励下一代国际地质微生物学家;以及3）提高对生物学和地质学之间的基本相互作用、化能无机营养过程以及生物技术、生物能源、和生物信息学。最终更广泛的影响结果将是一批科学启蒙和国际参与的年轻美国领导人。机构目标包括：1）在中美两国的个人和机构之间建立一个强大的长期研究和教育合作网络; 2）加强该项目在美国机构的项目，让更多的美国学生参与国际研究;和3）通过开发永久的，通过在中国、美国和其他国际论坛的主要专业会议上展示项目成果，参与的美国院校包括内华达州大学拉斯维加斯分校、格鲁吉亚大学、迈阿密大学（俄亥俄州）、蒙大拿州立大学、北方亚利桑那大学、亚利桑那州立大学、弗朗西斯科州立大学（加利福尼亚州）和斯坦福大学（加利福尼亚州）。参与的中国机构包括中国科学院、同济大学、云南大学、中国地质大学（北京）、中国地质大学（武汉）和厦门大学。该奖项由国际科学与工程办公室、地球科学部、环境生物部和NSF的EPSCoR项目共同资助。

Despite tremendous progress made since Brock's pioneering work in Yellowstone National Park in the 1960s and 1970s, our understanding of ecological processes at high temperature remains limited. This PIRE project builds on an existing foundation of collaboration between US and Chinese geobiologists to nucleate a large, international team to focus on the microbial diversity, biogeography, and ecosystem-level functioning within geothermal source pools in the largest hot spring complex in China, the Tengchong Geothermal Field in Yunnan Province. The long-term goal of this project is to develop a holistic and global view of geobiology in geothermal systems to complement and build upon what is known about life in other geothermal sites, such as Yellowstone National Park. In addition, US students and scientists will have a unique opportunity to experience the biologically-, geologically-, and culturally-diverse regions in southwestern China and develop long-lasting international collaborations.The study of high temperature ecosystems (73°C) is a frontier in biology because energy that supports these ecosystems is derived from chemical disequilibria rather than light. The expertise of this PIRE team enables it to test the central hypothesis that geographically distinct hot spring systems host genetically distinct microbial communities with similar carbob (C)- and nitrogen (N)-cycle functions. This hypothesis will be tested by focusing on bulk water and sediment microbial communities in source pools of six hot springs that represent three major physicochemical classes. The project's research objectives are: 1) to define hot springs as physicochemical habitats for microorganisms through extensive geochemical analysis and thermodynamic modeling; 2) to robustly define microbial community structure from both a phylogenetic and gene content perspective through deep sequencing of 16S rRNA gene fragments, whole community metagenomics, and fluorescent in situ hybridization; 3) to measure rates of carbon-cycling processes and trace assimilated carbon into key players in the C-cycle through DNA and lipid stable isotope probing, and C and Hydrogen natural abundance stable isotope measurements; 4) to apply a comprehensive suite of nitrogen-cycle process rate measurements combined with deep sequencing of N-cycle genes and transcripts to link processes to key players in the N-cycle; and 5) to sequence genomes of cultivated organisms to reveal possible roles in biogeochemical cycles, particularly C- and N-cycles, and microbial endemism on the genome scale. The combination of careful site characterization, direct measurement of microbial activities, and genomic approaches will lead to an unprecedented, integrated understanding of this system. When combined with similar work underway in the US, the team will gain a detailed window into the relative roles of geochemistry and biogeography in controlling microbial community structure and function.The educational goals of the project include: 1) Engaging U.S. graduate and undergraduate students, Nevada high-school science teachers, early-career researchers, the international geomicrobiology community, and the general public in globally-based scientific research and international collaboration; 2) motivating the next generation of internationally-engaged geomicrobiologists; and 3) increasing awareness of fundamental interactions between biology and geology, the process of chemolithotrophy, and the process and societal implications of advances in biotechnology, bioenergy, and bioinformatics. The ultimate broader impacts outcome will be a cohort of young US leaders who are scientifically-enlightened and internationally-engaged. Institutional goals include: 1) Developing a strong network of long-term research and educational collaborations among individuals and institutions in the US and China; 2) strengthening programs at the project's US institutions to engage more US students in international research; and 3) actively engaging the worldwide geomicrobiology community by developing a permanent, open and interactive website and data portal and by showcasing project results in major professional meetings in China, in the US, and in other international forums. Participating US institutions include the University of Nevada - Las Vegas, University of Georgia, Miami University (Ohio), Montana State University, Northern Arizona University, Arizona State University, San Francisco State University (CA), and Stanford University (CA). Participating Chinese institutions include the Chinese Academy of Sciences, Tongji University, Yunnan University, China University of Geosciences - Beijing, China University of Geosciences - Wuhan, and Xiamen University.This award is co-funded by the Office of International Science and Engineering, the Division of Earth Science, the Division of Environmental Biology, and NSF's EPSCoR Program.