AbstractAt deep-sea hydrothermal vents, microbial communities thrive across geochemical gradients above, at, and below the seafloor. In this study, we determined the gene content and transcription patterns of microbial communities and specific populations to understand the taxonomy and metabolism both spatially and temporally across geochemically different diffuse fluid hydrothermal vents. Vent fluids were examined via metagenomic, metatranscriptomic, genomic binning, and geochemical analyses from Axial Seamount, an active submarine volcano on the Juan de Fuca Ridge in the NE Pacific Ocean, from 2013 to 2015 at three different vents: Anemone, Marker 33, and Marker 113. Results showed that individual vent sites maintained microbial communities and specific populations over time, but with spatially distinct taxonomic, metabolic potential, and gene transcription profiles. The geochemistry and physical structure of each vent both played important roles in shaping the dominant organisms and metabolisms present at each site. Genomic binning identified key populations of SUP05, Aquificales and methanogenic archaea carrying out important transformations of carbon, sulfur, hydrogen, and nitrogen, with groups that appear unique to individual sites. This work highlights the connection between microbial metabolic processes, fluid chemistry, and microbial population dynamics at and below the seafloor and increases understanding of the role of hydrothermal vent microbial communities in deep ocean biogeochemical cycles.
|Project Title||Modeling how virus-microbe interactions influence carbon flow at a deep-sea volcano|
|Created||August 1, 2017|
|Modified||August 3, 2017|
In order to break open the black box of deep-sea hydrothermal vent microbiology and take our understanding of subseafloor microbial processes and the carbon cycle to a new level, we propose to investigate autotrophy in the rocky subseafloor using molecular biological, cultivation, and geochemical techniques at Axial Seamount, an active submarine volcano that will soon be part of a seafloor cabled observatory. In line with the Moore Foundation’s MMI objectives, this project will address the functional roles of various autotrophic subseafloor microbial community members across temperature and metabolism classifications; their relationships with each other, with viruses, and with other sources of syntrophic metabolic energy; and their collective impact on carbon biogeochemistry as dictated by environmental gradients in temperature and geochemistry. Of particular importance is the inclusion of seafloor experimentation at Axial, which will not only yield data on microbial activity and carbon transformations in situ, but will also set the stage for integration of a microbial instrument at the Axial cabled observatory. Our comprehensive suite of land-based, shipboard, and in situ analyses will yield cross-disciplinary advances in our understanding of the microbial ecology and geochemistry of carbon cycling in the subseafloor biosphere at mid-ocean ridges.
|Julie A. Huber||Woods Hole Oceanographic Institution (WHOI)||Lead Principle Investigator||✓|
|David A. Butterfield||National Oceanic and Atmospheric Administration (NOAA-PMEL)||Co-Principal Investigator|
|James F. Holden||University of Massachusetts Dartmouth (UMass Dartmouth)||Co-Principal Investigator|
|Jullie Zeigler Allen||J. Craig Venter Institute (JCVI)||Co-Principal Investigator|
|Joseph J. Vallino||Marine Biological Laboratory (MBL)||Co-Principal Investigator|