Evidence of microbial activity in a uranium roll-front deposit: Unlocking their potential role as bioenhancers of the ore genesis Jroundi, Fadwa Povedano Priego, Cristina Pinel Cabello, María Merroun, Mohamed Larbi Roll-front deposit Metatranscriptomics Microbial metabolisms Uranium Ore genesis ISR Uranium(U) roll-front deposits constitute a valuable source for an economical extraction by in situ recovery (ISR)mining. Such technology may induce changes in the subsurfacemicrobiota, raising questions about the way their activities could build a functional ecosystem in such extreme environments (i.e.: oligotrophy and high SO4 concentration and salinity). Additionally, more information is needed to dissipate the doubts about the microbial role in the genesis of such U orebodies. A U roll-front deposit hosted in an aquifer driven system (in Zoovch Ovoo, Mongolia), intended for mining by acid ISR, was previously explored and showed to be governed by a complex bacterial diversity, linked to the redox zonation and the geochemical conditions. Here for the first time, transcriptional activities of microorganisms living in suchU ore deposits are determined and theirmetabolic capabilities allocated in the three redox-inherited compartments, naturally defined by the roll-front system. Several genes encoding for crucialmetabolic pathways demonstrated a strong biological role controlling the subsurface cycling ofmany elements including nitrate, sulfate, metals and radionuclides (e.g.: uranium), through oxidation-reduction reactions. Interestingly, the discovered transcriptional behaviour gives important insights into the good microbial adaptation to the geochemical conditions and their active contribution to the stabilization of the U ore deposits. Overall, evidences on the importance of these microbial metabolic activities in the aquifer system are discussed that may clarify the doubts on the microbial role in the genesis of low-temperature U roll-front deposits, along the Zoovch Ovoo mine. 2023-06-15T11:45:41Z 2023-06-15T11:45:41Z 2022-12-02 info:eu-repo/semantics/article F. Jroundi et al. Evidence of microbial activity in a uranium roll-front deposit: Unlocking their potential role as bioenhancers of the ore genesis. Science of the Total Environment 861 (2023) 160636[http://dx.doi.org/10.1016/j.scitotenv.2022.160636] https://hdl.handle.net/10481/82509 10.1016/j.scitotenv.2022.160636 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier