ANR PHOSTOREPhosphorus sequestration: contribution of magnetotactic bacteria in oxic–anoxic transition zones

The ANR PHOSTORE (PI Elodie Duprat) stems from our recent demonstration that magnetotactic bacteria (MTB) of the Magnetococcaceae family strongly accumulate P as polyphosphate intracellular inclusions (PolyP), at the oxic-anoxic interface in the water column of the ferruginous Lake Pavin (Massif Central; Rivas-Lamelo et al. 2017, Geochem. Persp. Lett.). These bacteria constitute a new and relevant model for studying the cycling of P by microorganisms in freshwater environments, the molecular mechanisms of P sequestration and their influence by environmental parameters.

This project, with an inherent questioning about the interactions between living systems and solid inorganic phases, aims at (i) identify MTB strains particularly efficient in the accumulation of PolyP, (ii) measure the size and dynamics of this P-reservoir and therefore the impact of MTB on the P cycle in Lake Pavin, by their active storage of P in the biomass and by favoring the precipitation of phosphate mineral phases, and (iii) determine the genetic, metabolic and environmental determinants of these processes. In the longer term, this project may feed applications such as the development of bioremediation strategies.

Four research institutes are involved: the IMPMC (coordinator), the Institute of Biosciences and Biotechnologies of Aix-Marseille, the Institute of Physics of the Globe of Paris and the Laboratory Microorganisms: Genome and Environment of Clermont-Ferrand. This consortium combines recognized expertise in microbiology and ecology of MTB, (bio)mineralogy and geochemistry of solid and aqueous phases, environmental genomics, field and laboratory work.

The kick-off meeting was held on January 13, 2020 at Pierre and Marie Curie site of Sorbonne University.