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.
