Toxicity of copper, nickel, manganese and cadmium on cyanobacterium Hapalosiphon stuhlmannii

Abstract

The toxicity of nickel, cadmium, copper and manganese on the growth, nucleic acids, protein and heterocyst frequency of Hapalosiphon stuhlmannii has been studied. All the heavy metals tested were found to be toxic/inhibitory on the growth. It was also found that all test heavy metals have inhibitory effects at molecular level. Further, various morphological observations were also made such as granulation, depigmentation, variation in cell size and shape and formation of multicellular thallus.