A study of Manganese (Mn) oxides provides new details about biogeochemical mechanisms that could affect the preservation of organic carbon, and how Mn oxides can act as a reservoir for carbon in varied environments. The way in which organic carbon is preserved in an environment is related to its availability for microorganisms, and is important in understanding resource availability for microbes in extreme environments like the deep subsurface.

Scientists examined Manganese (Mn) oxides to better understand their role as a carbon reservoir in varied environments, and how Mn oxides might selectively partition particular carbon species. The team found relatively high levels of organic carbon associated with natural Mn oxide precipitates found in brackish waters, and Mn oxides produced biologically my Mn(II)-oxidizing marine bacteria and terrestrial fungi. Lower levels of organic carbon were found in ferromanganese cave deposits.

The paper, “Biogenic manganese oxides as reservoirs of organic carbon and proteins in terrestrial and marine environments,” was published in the journal Geobiology. The work was supported by NASA Astrobiology through the Exobiology & Evolutionary Biology Program.