Maxime Fuster

Maxime Fuster Understanding microbial iron metabolisms in deep-sea environments by bioreactors approaches.  or Monitor the growth of microorganisms in hydrothermal chimneys of the deep sea, depending on different temperature conditions.

Maxime is working on samples from the oceanic campaign BICOSE 3, which took place between October and December 2023. During this campaign, they got up the part of an active chimney and reduced it to powder. This powder enabled them to seed two bioreactors. Researchers use these bioreactors as vats where they can regulate each parameter (temperature, pH, gas composition…) filled with the fluids from the chimneys (hydrothermal fluids) and chimney powder. One of the bioreactors simulated an active chimney with an 80°C temperature (176°F), a stable pH (6.5) and without oxygen. The other one simulated a chimney with a lowering activity with a 20°C temperature (68°F), the same pH, and with oxygen. When the activity of the chimneys is lowering, the gas balance becomes different, with the presence of oxygen.

The aim of Maxime is to follow the development of these procaryotes microbial communities (Bacteria and Archea), in other words organisms whose cells have no nucleus, in those reactors and observe how they change over 30 days. Is there a growth, or contrary, a decline? What bacteria and archaea will be present in the bioreactors? Will they be the same in both or will they be different? Over that Maxime will analyze the genes of bacteria to try to understand why some of them have particular capacities, all that linked to iron cycle.

Why this subject ?

Maxime chose that subject because he found it pioneering and enabled him to highlight and improve some of its skills, especially in bio technology. Beside, working on the seabed area is, for him, passionate and necessary in the ecological context of today.