Postdoc: Neha Mehta (directors: Karim Benzerara, and Thierry Azais. Institute of Material grant, Sorbonne University)
Several strains of cyanobacteria were shown to form intracellular amorphous calcium carbonate (ACC) inclusions. Unlike pure abiogenic ACC that rapidly transforms to crystalline polymorphs, ACC found in cyanobacteria remains stabilized intracellularly with no obvious spontaneous transformation to crystalline phases. However, the mechanisms underlying such stability of ACC remain unknown. Here, we propose to address these questions using a combination of spectroscopy tools such as solid-state NMR spectroscopy, FTIR spectroscopy, and synchrotron-based X-Ray Absorption spectroscopy. The findings from this project have potential to provide the first clues about the stability of not only cyanobacterial ACC, but also shed some light on the formation, occurrence, and crystallization of ACC in other ACC forming prokaryotes.
Figure: 13C CP NMR spectra of ACC forming cyanobacteria (red) and non-ACC forming cyanobacteria (blue). Broad peak at ~169 ppm corresponds to ACC, and is only present in ACC forming cyanobacteria.
@ Neha Mehta
