Comparison of the detoxication capacity of the limnic and marine form of the green algae Enteromorpha compressa

The chlorophyte macroalgae, Enteromorpha compressa, is found in freshwater as well as marine environments. The freshwater form is present only for a short time, from late May to July, whereas the marine form is present along the coast throughout the year. In this study we compared the detoxication capacity of this algae from both ecosystems to investigate why the freshwater form shows such a shortened lifespan. We measured the activity of the guajacol peroxidase and of the microsomal and soluble glutathione S-transferase, two enzymes representing the Phase I (peroxidase) and Phase II (microsomal and soluble glutathione S-transferase) detoxication systems. Furthermore, we investigated the activity of glutathione reductase, an enzyme related to maintenance of the glutathione pool. We found that the marine form of E. compressa has lower enzyme activities compared with the limnic algae, whereas the substrate specificity of both forms seems to be equal.