“…Manganese and iron microbial oxidation was documented for various environments, such as in deep sea hydrothermal plumes (Dick et al ., ), on soil surfaces (Zhang et al ., ), in rivers (Shiller and Stephens, ) and other habitats (Ehrlich, ; Emerson, ; Spiro et al ., ). In addition, a number of fungi isolated from soils, sludge, sediments and drinking‐water distribution systems has been reported as being capable of oxidizing Mn(II) (Schweisfurth, ; Sterflinger, ). Microorganisms with such physiological properties have been suggested to play an active role in varnish formation (Dorn and Oberlander, ; Taylor‐George et al ., ; Hungate et al ., ; Dorn, ; Perry et al ., ; Schelble et al ., ; Kuhlman et al ., ; Gorbushina, ; Kuhlman et al ., ; Zhang et al ., ).…”