The primary objective of this project is to determine which microorganisms are involved in CO2 fixation and Mn oxidation in hydrothermal vent systems. The researchers will employ biogeochemical, microbiological, and molecular biological methods to gain a more complete understanding of the microbial communities that are coupling metal oxidation to carbon fixation, thus driving basalt weathering and sustaining ecosystems in the deep-sea. Their strategy includes 1) culture-based methods to isolate more ecologically significant strains and to determine whether Mn-oxidizing bacteria may play a role in fixation of inorganic carbon into organic carbon in mixed or pure cultures, 2) culture-independent methods to identify the key chemolithoautotrophic organisms responsible for carbon fixation in the environment, and 3) peptide probes to physically separate Mn oxides and associated microorganisms from other particles and microbes; analysis of macromolecules (DNA and/or lipids) of the Mn oxide-associated microorganisms will provide the first direct phylogenetic identification of the organisms responsible for Mn oxide biomineralization in environmental samples.
Broader Impacts: Isolating autotrophic Mn(II)-oxidizing bacteria from hydrothermal fields, the main objective of this project, will have a broad impact on understanding the manganese cycle. The postdoctoral candidate has already a great track record of outreach and education activities during her Ph.D. studies, and the proposed collaboration with high school students is a great value to the broad impact of this work.
