M-CARBO-STORE

The M-Carbo-Store project examines the link between increasing atmospheric CO₂ and its sequestration as carbonates through microbial processes. The focus is on carbonate mud deposits in diverse environments shaped by climatic, sedimentary, and diagenetic factors. The project aims to synthesize carbon fluxes and longterm storage in carbonate muds across continental and marine settings, seeking to understand precipitation conditions and microbial mechanisms crucial for carbonate formation and carbon sequestration. WP1 will map and estimate carbonate volumes along a mangrove-to-marine transect in New Caledonia, expanding on previous continental studies. It will investigate variations in carbonate production related to exopolysaccharides (EPS) degradation, testing the applicability of lake processes to marine lagoons. WP1 will use core sampling, advanced analyses, and radiocarbon dating to provide detailed mapping, volume estimates, and a model of mud formation. WP2 studies fluid and organic variability across environments, while WP3 and WP4 investigate microbial roles and carbonate mineralogy for long-term carbon storage.

The project is a collaborative effort involving international experts in geomicrobiology, mineralogy, and chemistry, with local support from Bourgogne-Franche-Comté (BFC) for fluid and sediment analyses. It utilizes advanced techniques like geophysics, Raman spectroscopy, Cryo-SEM, ICP-MS, XRD, and isotopic analysis. Samples collected from fieldwork will provide estimates of carbon fluxes during mud formation. Research includes characterizing and quantifying EPS, analyzing microbial community diversity, and conducting mineralogical and geochemical studies of carbonate muds to support long-term carbon storage insights.

A postdoctoral researcher will assist with analytical protocols, gaining multidisciplinary skills and enhancing visibility in the geobiology community. The project addresses climate change challenges through collaborations with American and Swiss research groups. It also involves colleagues from INRAE, Chrono-environment, and Biogéosciences in BFC, contributing to the HARMI initiative throughout their WP1 on microbial community dynamics in response to climate change, and WP3, focusing on managing microbial communities for climate change mitigation. The M-Carbo-Store project will foster cross-disciplinary knowledge exchange -spanning biology, geomicrobiology, chemistry, and earth sciences -advancing our understanding of microbial-mediated carbonate precipitation for long-term carbon storage.