Response of the ascorbate-peroxidase of Selenastrum capricornutum to copper and lead in stormwaters

The green alga Selenastrum capricornutum expresses a unique ascorbate perox idase, that responds to copper and lead. Attempts were made to test if this peroxidase could be used to monitor the levels of copper and lead in natur al waters. When S. capricornutum was exposed to a stormwater sample, the sp ecific activity of the peroxidase in the cell extract was commensurate with the combined copper and lead contents in the sample. The peroxidase respon ses were also correlated with the 96 hr biomass toxicity assay of S. capric ornutum. However, unlike the biomass toxicity assay, the peroxidase activit y was not affected by the anions in the samples. The use of this peroxidase can be used as a marker for testing heavy metal toxicity in the water.