Nickel uptake and its localization in a cyanobacterium

Abstract

Nickel bioconcentration in different cell preparations of the cyanobacterium Nostoc muscorum was examined. A two- or three-fold increase in phosphate concentration over that prescribed in growth medium (58 μM), favoured nickel accumulation restricted to a threshold limit. Intact cells showed highest nickel bioconcentration (8.41 μmol mg-1 dry wt) over spheroplasts (6.19 μmol mg-1 dry wt) or polyphosphate bodies (5.88 μmol mg-1 dry wt). Such preparations derived from similar cells indicate that the cyanobacterial cell wall could accommodate around 14-19% of the total nickel taken in by the cell with the overall nickel-bioconcentration sequence as: intact cells > spheroplasts > polyphosphate bodies > cell wall. The data suggest that polyphosphate bodies are the main sink for nickel. © 1992.