A mile or more below the surface of the ocean, microbes dominate the deep sea life. In this seminar, Dr. Julie Huber describes her research to better understand the microbial ecosystem in the rocky crust below the ocean floor. She begins the series by describing how reactions between seawater and the elements in ocean rocks enable chemosynthetic ecosystems to exist in the deep sea. She then introduces us to the tools scientists use to study microbial deep sea life below the ocean floor.
In her second talk, Dr. Huber describes her research, which integrates microbiology, molecular biology, and ocean sciences approaches to characterize the microbial ecosystem below Axial Seamount, an underwater volcano off the coast of Oregon. Dr. Huber outlines how her group used environmental DNA and RNA sequencing techniques to analyze the crustal fluids (mix of ocean water & hydrothermal vent fluid) leaking from underneath the sea floor at three deep-sea vents. Her group determined that the metabolic potential of organisms was similar across vents (as indicated by DNA sequencing) but that there were larger differences in the “activity” of the microbes across vents (as indicated by mRNA profiling). Furthermore, Dr. Huber’s group identified vent-specific subseafloor microbial populations.
In her third talk, Dr. Huber describes how a method known as RNA stable isotope probing (SIP) was used to characterize the metabolically active autotrophic microbes at an underwater vent at Axial Seamount. Dr. Huber’s group found that temperature influences the metabolic pathways, including the carbon fixation pathways, used by different organisms collected at the same vent. In addition, Dr. Huber’s group compared microbial activity across three vents and found that all three have different microbes that are active in a similar temperature environment. These findings suggest that subseafloor microbes prefer some environments over others and use different metabolic pathways in different environmental contexts.
Julie Huber is an Associate Scientist of Marine Chemistry and Geochemistry at the Woods Hole Oceanographic Institution in Woods Hole, MA. Before joining the Oceanographic Institute, Huber was an Associate Scientist at the Marine Biological Laboratory, also in Woods Hole, for 10 years. Her lab studies the microbial life found in the unique, and largely… Continue Reading