Action of selected heavy metal ions on the photosystem 2 activity of the cyanobacterium Spirulina platensis

Abstract

Addition of different concentrations of heavy metal ions (Hg2+, Cu2+, Ni2+ and Pb2+) inhibited the photosystem 2 catalyzed electron transport activity (H2O→p-benzo-quinone) of the cyanobacterium Spirulina platensis. Hg2+ caused the inhibition in electron transport activity in very low concentrations compared to the other metal ions. Hg2+ at this low concentration specifically altered the spectral properties of phycocyanin of the phycobilisomes in the intact cells of Spirulina, whereas other heavy metal ions were ineffective in this sense. © 1995 Institute of Experimental Botany, ASCR.