Influence of Inorganic Nitroge N-Nutrients on Copper Toxicity in Anacystis nidulans and Cyanophage As-I Resistant Mutant

The effect of different nitrogen sources on growth and copper toxicity was studied in the unicellular cyanobacterium Anacystis nidulans and Gyanophage AS-1 resistant mutant (An/AS-1). The mutant An/AS-1 was characterised by slow growth rate but was more senstitive to copper than its parent. In both the strains, the presence of high nitrate concentrations, which supported better growth of algae, reduced the algicidal effect of copper. However, other inorganic nitrogen sources such as nitrite and ammonium caused more inhibition and reduced the specific growth rate.