Growth, antioxidant response and microcystin production by Microcystis aeruginosa exposed to the surfactant perfluorooctanesulfonic acid (PFOS)

ABSTRACT The surfactant perfluorooctanesulfonic acid (PFOS) is used in various products, but its impact on aquatic organisms like cyanobacteria is poorly understood. PFOS was tested for acute toxicity on the cyanobacterium Microcystis aeruginosa in terms of growth, photosynthetic pigment content, antioxidant response and microcystin production. When exposed to PFOS, the cyanobacterium was sensitive to it, showing significant inhibition of growth and reduction of pigment content. At the same time, exposure to PFOS resulted in a two-fold increase of the content of total carbohydrates and soluble proteins in the cells of M. aeruginosa. There was a significant increase in MDA and H2O2 levels in cells exposed to PFOS, but not in a concentration-dependent manner. Microcystin content tended to increase in PFOS-exposed cyanobacterial cells, although this change was not statistically significant (p > 0.05). These findings suggest that when surfactants like PFOS are used in large quantities or concentrations, they could adversely affect Microcystis populations in the aquatic environment.