Manganese and phosphate removal from culture medium during the growth of the bacterium Sphaerotilus montanus.

Abstract

The ability of bacteria to absorb metal ions and phosphates allows the development of processes for bioremediation of the environment and wastewater from heavy metals and excess phosphates. In this work, the ability of the "iron bacterium" Sphaerotilus montanus VKM B-2519 to remove manganese, iron, and phosphate from culture medium was studied. The bacterium removed Mn²⁺ but not Fe²⁺ from the culture medium during growth. At an initial concentration of 3 mmol/L Mn²⁺, about 40% of phosphate and no more than 10% of manganese remained in the medium after cultivation of S. montanus for the stationary stage. Inorganic polyphosphate did not contribute to the removal of phosphate by S. montanus. In the presence of excess Mn²⁺, S. montanus formed Mn₃(PO₄)₂ as a precipitate. It was confirmed by both chemical analysis and EDX. In the presence of excess Mn²⁺, S. montanus secreted phosphorylated exopolysaccharide into the culture medium. The data suggested that S. montanus VKM B-2519 is a prospective species for developing phosphate and manganese removal and biological sedimentation of manganese phosphate.