Oceanography SeminarJanuary 16, 3:00pm - 4:15pm
Mānoa Campus, MSB 100
SOEST Young Investigator
Department of Oceanography
“Linking microbial ecology to metabolic activity in deep sea hydrothermal vents”
Abstract: At hydrothermal vents, thermal and chemical gradients generated by the mixing of hydrothermal fluids with seawater provide diverse niches for prokaryotic communities. To date, our knowledge of environmental factors that shape prokaryotic community composition and metabolic activities across these gradients within the active sulfide structures is limited. Few studies exist regarding the detailed spatial relationships between vent geochemistry and the abundance, distribution, and metabolic characteristics of the endolithic hosted communities. Even fewer data have been generated on the magnitude of metabolic rates and factors controlling the kinetics of these reactions have not been well constrained. The goal of this work was to better understand microbially mediated sulfur cycling at hydrothermal vents by allying phylogenetic identity to metabolic potential and rates of sulfur metabolism within hydrothermal chimneys. This work features the use of an in situ sulfide microbial incubator to characterize de novo endolithic prokaryotic communities with spatially co-registered temperature within a hydrothermal vent chimney and radioisotopic 35S-tracer techniques to elucidate the metabolic activity of these communities. Based on analyses of taxonomic and metagenomic data the observed differences in community composition may be due in part to physiological tolerances of specific microbial taxa, as well as the metabolic capacity of each community. Furthermore, the rates of sulfate reduction presented here suggest that-within anaerobic niches of hydrothermal deposits-heterotrophic sulfate reduction may be quite common and might contribute substantially to secondary productivity, underscoring the potential role of this process in both sulfur and carbon cycling at vents.
Oceanography, Mānoa Campus