Award: OCE-1136451

Award Title: Dimensions: Collaborative Research: An Integrated Study of Energy Metabolism, Carbon Fixation, and Colonization Mechanisms in Chemosynthetic Microbial Communities at Deep-Sea Vents
Funding Source: NSF Division of Ocean Sciences (NSF OCE)
Program Manager: David L. Garrison

Outcomes Report

The biological communities that inhabit deep-sea hydrothermal vents are supported by chemosynthetic microorganisms that convert the energy associated with inorganic chemical species of volcanic origin into biochemical energy (ATP), which in turn is used to convert carbon dioxide into organic carbon. In particular, bacteria belonging to the Epsilonproteobacteria and Aquificales play an important role as primary producers at deep-sea hydrothermal vents. Epsilonproteobacteria and Aquificales exhibit similar metabolisms – i.e. the oxidation of reduced sulfur compounds and hydrogen with both oxygen and nitrate or the oxidation of hydrogen with elemental sulfur coupled to the fixation of inorganic carbon – and thus occupy a similar ecological niche, but at different temperatures (Epsilonproteobacteria: 20°C - 70°C; Aquificales: 60°C - 90°C). However, little is known about the preferential or simultaneous use of these alternative e-donors/acceptors and the conditions under which the corresponding enzymes are expressed. In the course of this study, we elucidated some of the central metabolic pathways used by microorganisms that colonize deep-sea vents by forming biofilm communities. Overall our observations indicate that, by fixing CO2 via the reductive tricarboxylic cycle (rTCA) and conserving energy via the reduction of nitrate to either dinitrogen gas or to ammonium, vent bacteria are of particular interest as they link the carbon and nitrogen cycles at in these geothermal habitats. We also investigated how vent Epsilonproteobacteria communicate among each other via chemical signaling (quorum sensing) and we showed that pathogenic members of this group of bacteria inherited the quorum sensing pathways from their thermophilic bvent relatives. Major outcomes from this project include thirteen peer-reviewed publications and an article for the general public soon to be published in the magazine Scientia. Further information about this project was disseminated on the Deep-Sea Microbiology Lab website (https://marine.rutgers.edu/deep-seamicrobiology/index.html), including a description of the oceanographic expedition sponsored by this project (https://marine.rutgers.edu/deep-seamicrobiology/at26-10.html), photo and instructional videos (https://marine.rutgers.edu/deep-seamicrobiology/gallery.html) and the Lab's rationale to study the phisiology (https://marine.rutgers.edu/deep-seamicrobiology/Physiology.html), ecology (https://marine.rutgers.edu/deep-seamicrobiology/Ecology.html) and evolution (https://marine.rutgers.edu/deep-seamicrobiology/Evolution.html) of marine prokaryotes. Last Modified: 05/12/2017 Submitted by: Costantino Vetriani

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Principal Investigator: Costantino Vetriani (Rutgers University New Brunswick)