Ph.D. Student Juliette Gaëtan (Supervisors : K. Benzerara, J.Leloup (iEES-Paris))

I’m working on the biomineralization of intracellular calcium carbonates (iACC) in bloom-forming cyanobacteria. I’m focusing on Microcystis, a freshwater genus that is extensively studied for its capacity to bloom in eutrophic environments. I’m interested in the impact of the formation of iACC on the environment during bloom events. The main aim is to understand if Microcystis can be a significant CaCO₃ reservoir during bloom. For that, I follow several lakes around Paris. The second part of the project is to assess if the capability to form intracellular CaCO3 provides specific ecological traits/behaviors to some Microcystis strains. This part is based on laboratory experiments on environmental strains to test their growth and buoyancy when incubated under variable conditions.

I’m using microscopy techniques such as SEM and TEM, but also spectroscopy (FTIR), solution chemistry (ICP-EAS, colorimetry, etc.), and microbiology (culture).

Figure :  SEM Image (AsB mode) of Microcystis cells forming iACC.

@ Juliette Gaëtan