Microbial communities associated with travertine deposits

To clarify the roles of microorganisms in the formation of peloidal carbonates, we analyzed microbial communities associated with recently precipitated aragonitic travertine at Satono-yu hot spring (Oita Prefecture, southwestern Japan). Fresh samples collected from active depositional zones were subjected to 16S rRNA gene amplicon sequencing to characterize microbial community composition. Based on community structure and microfacies observations, we hypothesize that cyanobacteria may have promoted carbonate grain growth and structural stabilization, thereby contributing to the development and preservation of peloidal pockets at the microfacies scale.