Effect of nickel and cadmium on ammonium uptake kinetics of free and immobilized cells of Anacystis nidulans; [Wirkung von nickel und cadmium auf die kinetik der ammonium-aufnahme freier und immobilisierter zellen von Anacystis nidulans]

Abstract

The stress effect of Ni and Cd on the ammonium uptake varied significantly (ANOVA test) in free and immobilized state of the test organism. The effect due to the interaction between different variables (cell state type, metal type and metal dose) was studied to depict the significant or non-significant variation in the ammonium uptake by free and immobilized cells in the presence of metal ions. Ammonium uptake exhibited a competitive mode of inhibition in the presence of Ni in both free and immobilized state of the organism. However, Cd exhibited non-competitive and competitive inhibition in free and immobilized cells, respectively. The study demonstrates that there is a considerable influence of metal ions on the ammonium uptake. Cd was found to be more toxic compared to Ni in both free and immobilized state. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.