Uptake of magnesium,strontium, barium,and manganese byPlectonema boryanum (Cyanophyceae) with special reference to polyphosphate bodies

Summary The ability of a cyanobacterium to take up and concentrate metals in polyphosphate bodies was tested. It was found that Mg, Ba and Mn are taken up by 3 and 4 week old cultures ofP. boryanum and in all cases the metals were concentrated in the polyphosphate bodies. In the case of Mn it was also detected in the cytoplasm. Strontium was sometimes taken up and incorporated into dense bodies which contained Sr, high S, high K and low Ca. In a number of trials no uptake of Sr could be detected. Polyphosphate bodies, formed as a result of the overplus phenomenon did not incorporate the metal at the time they are being formed. Polyphosphate bodies from 2 and 3 week culture contain P, K, Ca and Mg while bodies from 4 week cultures also possess Zn.It is suggested that sequestering metals in polyphosphate bodies may be a significant mechanism by which heavy metals are concentrated.