[Accumulation and precipitation of Mn2+ by the cells of Oscillatoria terebriformis].

The cyanobacterium Oscillatoria terebriformis was shown to exhibit resistance to high manganese concentrations, remaining viable at 2.5 mM MnCl2 in the medium. Cyanobacterial cells were capable of considerable manganese consumption from the medium. Dynamics of Mn sorption by the cells was the same in all experimental variants, independent on the manganese concentration. Manganese concentration in the biomass peaked after 2-3 days and depended on Mn2+ concentration in the medium and on the amount of biomass introduced. In the case of O. terebriformis, manganese removed from the medium may be subdivided into Mn absorbed by the cell, Mn bound to the cell wall, Mn absorbed by the glycocalix, and chemically precipitated Mn. Of the total 21.25 ± 1.0 mg of consumed manganese, biological absorption and chemical precipitation were responsible for 11.78 ± 0.98 and 9.2 ± 0.8 mg, respectively. In the presence of cyanobacteria, Mn removal from the medium was 2.28 times higher than in the control. This process depended considerably on Mn sorption by exopolysaccharides. At 1.3 mM Mn2+, a lamellar mat was formed with interlayers of manganese carbonate.