Microbial carbon fixation in a marine shallow-water hydrothermal vent system

Carbon fixation pathways and microbial metabolism based on arsenic in the marine shallow-water hydrothermal system of Palaeochori Bay, Milos Island, Greece

The overarching objective for this project is to evaluate microbial community structure of the marine shallow-water hydrothermal vent system of Palaeochori Bay, Milos Island, Greece, and to shed light onto their carbon fixation strategies. Our research focuses on in-depth examination of the importance of photo- versus chemoautotrophic processes as well as on the evaluation of metabolisms based on the disequilibrium between reducing hydrothermal fluids and overlying oxidized seawater, specifically arsenic redox.
Profound information about the microbial carbon cycling in submarine shallow hydrothermal vent systems is necessary in order to get a deeper understanding of the functioning of these systems, which have a high influence on surrounding areas due to discharge of e.g. arsenic and which are systems that might be useful early Earth analogs.
The project is a collaboration with Dr. Roy Price (https://www.marum.de/en/Roy_Price.page), an expert in geochemistry of shallow hydrothermal vent systems.
In addition to an in-depth geochemical characterization of different habitats at the vent site, our goals will be achieved by a combined approach using lipid biomarker analyses and 13C-labeling experiments at near in situ conditions on one hand, and molecular microbiological methods as well as enrichment experiments on the other.
I especially aim to:
1) characterize the microbial community structure of habitats set apart by (i) different light regimes and (ii) arsenic species, using lipid chemotaxonomy, and
2) pinpoint autotrophic processes to organisms using 13C-labeling experiments.

Funding: MARUM Incentive Fund (PIs: Roy Price and Solveig Bühring)
Participating scientists:
Kai-Uwe Hinrichs, Department of Geosciences and MARUM Center for Marine Environmental Sciences, University of Bremen;
Thomas Pichler, Department of Geosciences, University of Bremen,
Anke Meyerdierks, Max Planck Institute for Marine Microbiology,
Jan Amend, Washington University, St. Louis, USA;
Miriam Sollich, Diploma student, University of Bremen,
Bastian Piltz, MarMic Student, Max Planck Institute for Marine Microbiology.

see also: Hydrothermal Arsenic at Milos

Roy Price measuring the in situ temperature (courtesy of Bastian Piltz)