Toxicity of single and combinations of lead and cadmium to the cyanobacteria anabaena flos-aquae

摘要

Cyanobacteria are prokaryotes that can synthesize chlorophyll a and hence are able to undergo photosynthesis. They are widespread and can be found in many different habitats from aquatic to terrestrial, and known to be tolerant towards conditions of low oxygen, nutrient deficient and free sulphide (Whitton and Potts 2000). The widespread nature of cyanobacteria in different environments makes this class of bacteria useful as indicator of environmental contamination and pollution. Indeed the use of cyanobacteria, such as Anabaena flos-aquae to remove heavy metals pollution in contaminated aquatic ecosystems have been studied quite extensively by many researchers. Some of the biological processes that involved biosorption (adsorption) and binding sites have been described by Chong and Volesky (1995). Gadd and White (1993) and Ting et al. (1991).