Different Forms of Microbial Manganese Oxidation and Reduction and Their Environmental Significance

A variety of bacteria have been found to be able to catalyze manganese oxidation. They can be divided into two major groups on a physiological basis. To one of these two groups are assigned those organisms that act on free Mn2+, and to the other group are assigned those organisms that can act only on Mn2+ bound to Mn(IV) oxide. Of the group that attacks free Mn2+ ions, some members seem to be able to derive energy from the reaction while others cannot. So far, all members of a group of seven different organisms that attack only Mn2+ bound to Mn(IV) oxide are able to get energy from the oxidation (Ehrlich, 1976, 1978a; unpublished data).