Formation of intracellular amorphous carbonates by bacteria
Karim Benzerara (Sorbonne Universités, Paris)
Living cells can sustain out-of-equilibrium states in a given environment by consuming free energy. The formation of some intracellular mineral phases provides some examples of this. Here I will review some of the work we have performed in the last years to describe and understand how some cyanobacteria, which are abundant photosynthesizing bacteria appeared several billions years ago at the surface of the Earth, manage to form intracellular amorphous carbonates. I will show the environmental conditions under which they catalyze this process, detail the methodologies (including cryo-TEM and spectroscopies) we used to characterize these phases and finally address the involved (bio)molecular mechanisms. The question of the selective advantage(s) provided by this process, if any, will be asked. The implications for basic and applied research will also be addressed. Overall, this talk should convince you that a highly interdisciplinary work is crucially needed to globally understand this intracellular biomineralization process.