Award: OCE-1136488
Award Title: Dimensions: Collaborative Research: An Integrated Study of Energy Metabolism, Carbon Fixation, and Colonization Mechanisms in Chemosynthetic Microbial Communities at Deep-Sea Vents
Outcomes Report
Overview: Hydrothermal vents are widely regarded as hotbeds of life in the deep ocean, although they were discovered only forty years ago. Hydrothermal fluids, originating within the Earth?s crust, are enriched in reduced chemical species. When these fluids mix with cold, oxygenated seawater, the resulting chemical disequilibria offer a source of energy for the growth of chemoautotrophic microorganisms. Subsequently, a plethora of larger organisms feed on these microbes, thus creating ecosystems that are independent of sunlight. Vents also serve as natural, semi-contained laboratories for studies of the evolution of life. The overarching aim of this project was to provide insights into the integrated roles of genetic and functional diversity of microorganisms in driving the biogeochemical cycling of carbon, nitrogen, sulfur and other elements in diffuse flow hydrothermal vents. Intellectual merit: Bigelow Laboratory?s contribution to this multi-party, collaborative research project centered around microbial single cell genomics. We obtained DNA from thousands of individual cells of bacteria and archaea from a diffuse-flow vent in the East Pacific. Of them, 127 cells were genomically sequenced, in order to represent the predominant lineages as well as novel evolutionary branches. Our data confirmed that this hydrothermal system is dominated by chemoautotrophs belonging to six genera of the Espilonproteobacteria phylum. We found that all cells of the predominant genera encoded and expressed essentially the same, multiple pathways for energy metabolism, which implies high degree of functional redundancy and versatility both among and within these genera. Functional redundancy and versatility are important features of vent microbial communities, since they provide resilience in the dynamic vent environment, where fluxes of elements vary dramatically in space and time. Single cell genome data also revealed interesting features of phage-host interactions in hydrothermal vents. We found no evidence for lytic infections, while prophage-like genetic elements were detected in about 10% of the sequenced cells. This is very different from the surface ocean, where we found frequent lytic infections and no signs of lysogeny in an earlier study. Prophages in vent microorganisms appear to contribute to the protection of their hosts against other viruses, toxic metals and anti-bacterial compounds. In addition to the improved understanding of the hydrothermal vent ecology, single cell genomics data also helped improving our understanding of the early evolution of life, by generating genomic sequences of several novel, deeply branching lineages of Bacteria and Archaea. Project?s data are available at http://www.bco-dmo.org/project/2216 Broader impacts: This project provided partial support for four postdoctoral associates who gained knowledge and experience in hydrothermal vent ecology, evolution, genomics, bioinformatics, project management, and communication of research results. Seven other professionals (computational and laboratory scientists) improved their professional skills through the engagement in various aspects of the project at Bigelow Laboratory. Two undergraduate students were involved in this project, with partial support from an REU program. The work of both students were deemed among the three best in respective groups, and they received travel awards to present their results at the Association for the Sciences of Limnology and Oceanography (ASLO). At least 10 students and postdocs are engaged in the continued analysis of this project's data and manuscript preparation at collaborating institutions. Improvements in the single cell genomics technology, partially supported by this project, were incorporated into Bigelow Single Cell Genomics Center?s (SCGC) services and provided the basis for a commercial product for a collaborating biotech company. The SCGC has provided its services to a wide range of research projects at more than 100 organizations around the globe. Additionally, we hosted the Third Microbial Single Cell Genomics Workshop in June 2015, which attracted 72 participants from 15 countries, including 16 students, 13 postdocs, 32 principal investigators and 11 other professionals. Last Modified: 07/17/2017 Submitted by: Ramunas Stepanauskas