Biological effects of surfactant-contaminated water on aquatic ecosystems: Effects on photosynthetic pigments and antioxidant defense systems of Lemna minor

Abstract

Anionic surfactants are widely used in many fields of technology and research due to their favorable properties and are considered as one of the most important factors in contamination of water resources. The presence of high concentrations of these compounds in aquatic environments induces oxidative stress and physiological changes in aquatic animals and threatens their life. In this study, the effects of 7 days exposure to concentrations of 0, 10, 20, 30 and 40 mg/l of linear alkylbenzene sulfanate surfactant was studied on lipid peroxidation, the activity of catalase enzyme, total carotenoid phenolic content, free proline, total chlorophyll content and membrane stability index in Lemna minor plant. The results showed that with increasing LAS concentration, the total chlorophyll content and carotenoid were reduced. The highest total phenol and free proline were observed in concentrations of 40 and 20 mg/l surfactant, respectively. Also, by increasing the concentration of surfactant, the activity of the enzyme catalase and lipid peroxidation increased and the minimum "membrane stability index" was observed in treated plants with a concentration of 40 mg/l of LAS. Concentrations of more than 20 mg/l of LAS caused significant toxicity in the plant Lemna minor.

Keywords

• lemna minor
• alkylbenzene
• sulfanate
• surfactant
• oxidative stress