Project description:Microbially induced carbonate precipitation (MICP) refers to the biogeochemical process in which calcium carbonate is precipitated by altering the local geochemical environment (Mortensen et al. 2011). These alterations occur as a by-product of common microbial metabolic activities by increasing the local carbonate content as well as pH thereby saturating the solution in respect to carbonate. To better understand the microbial ecology of MICP on a community level in natural environments, we chose to evaluate microbial communities derived from travertine adjacent to Crystal Geyser (CG), Utah. CG is a cold-driven, CO2 rich geyser which is surrounded by colorful travertine that has been suggested to be generated through microbial processes. We used a cultivation-independent, multi-omics approach combined with geochemical measurements to investigate metabolic pathways and physiologies potentially involved in MICP at CG. We collected samples from the top 20 cm of travertine adjacent to Crystal Geyser, Utah in November 2019 and June 2021 (38.9384° N, 110.1354° W) wearing gloves at all times. We sampled 1 m away from the borehole (CG-1) and 10 m away from the borehole (CG-10). We preserved all collected samples in RNAlater-like solution (Menke et al., 2017, Front. Microbiol. 8) in a 1:10 sediment: RNAlater-like solution ratio as previously validated (Jensen et al. (2021, Micro. Spec. 2021, 9:2)