Phosphorus biogeochemistry  

Phosphorus is central to the functioning of ecosystems as well as many strategies aiming at a sustainable management of environmental resources. Microorganisms have been shown to be major actors in modern and past geochemical cycles of P either as reservoirs and/or catalysts of processes exchanging P between different reservoirs. Over the last years, we have been developing several lines of research about 1) characterization of P species at the nanoscale, 2) polyphosphate formation, 3) biomineralization and fossilization of microbial cells by phosphate minerals

Characterization of P species at the nanoscale

Charaterization of P species by scanning transmission x-ray microscopy (STXM):
- identification of P mineral through Ca and P speciation
(Ca & P L2,3 edges)
- Quantification of carbonate substitution (C K-edge)

                Benzerara et al (2004) Geobiology

                Cosmidis et al (2015) Acta Biomaterialia

Geochimical impact of polyphosphate and Fe-phosphate  formation

Role and mechanisms of Fe-phosphate biomineralization in Lake Pavin

                    Cosmidis et al (2014) Geochim. Cosmochim Acta
                    Busigny et al (2016) Book chapter

Massive formation of polyphosphate by some magnetotactic bacteria in Lake Pavin

                    Rivas-Lamelo et al (2017) Geochemical Perspective Letters

Biomolecular mechanisms of calcification

Kinetics and localization of calcification by E. coli mutants surexpressing alkaline phosphatase phoA

Cosmidis et al (2015) Frontiers in Earth Science

In silico and in vitro analysis of diverse phosphatases involved in calcification

                    Skouri-Panet et al (2018) Frontiers in Microbiology

Fossilization of bacterial cells by calcification

FIB/TEM/STXM characterization of bacterial fossils in phosphorites/coprolites...
                    Cosmidis et al (20013) Chemical Geology
                    Cosmidis et al (2013) Geobiology
                    Zaton et al (2015) Palaeogeography, Paleoclimatology, Palaeoecology

Medical calcifications

Nanoscale characterization of so-called nanobacteria/microcalcifications

Benzerara et al (2006) Journal of Investigative Medicine

Bacterial involvement in the formation of some kidney stones
                    Marine Livrozet's PhD


Karim BENZERARA     Modified on December 23. 2018