Microbial Involvement in Carbon Transformation via CH4 and CO2 in Saline Sedimentary Pool

A study on the UNESCO-listed Wieliczka and Bochnia Royal Salt Mines reveals that microbial activity significantly influences carbon transformation through methane (CH4) and carbon dioxide (CO2), even under extreme saline subsurface conditions. The research found that methanogenic and methanotrophic microorganisms thrive primarily in water-saturated environments, with respiration rates ranging from 36 to 48 nmol CO2 per gram of dry weight per day. Methane production was highest in siltstone and sandstone samples (W3), while aerobic methane oxidation peaked in siltstone containing salt and anhydrite (W4). Stable isotope analysis suggested that methane oxidation may have altered the carbon isotopic composition (δ13CCH4) in these sediments. The study used microcosm experiments, high-throughput sequencing, and activity measurements to characterize microbial communities, highlighting the critical role of water activity in regulating microbial processes in saline subsurface ecosystems.

Goraj, W., Szafranek-Nakonieczna, A., Grządziel, J., Polakowski, C., Słowakiewicz, M., Zheng, Y., Gałązka, A., Stępniewska, Z., & Pytlak, A. (2021). Microbial Involvement in Carbon Transformation via CH4 and CO2 in Saline Sedimentary Pool. Biology, 10(8), 792. https://doi.org/10.3390/biology10080792