Toxicity response of Chlorella microalgae to glyphosate herbicide exposure based on biomass, pigment contents and photosynthetic efficiency

The extensive use of glyphosate (N-(phosphonomethyl) glycine) herbicide in agriculture is accompanied by the risk environmental contamination aquatic ecosystems. In this study, effects at different concentrations (50–500 µg ml-1) on three Chlorella species including ellipsoidea, sorokiniana and vulgaris especially relation to biomass, pigment contents photosynthetic efficiency were assessed. After treatment for 24 hr, acute toxicity results showed that C. (IC50 = 449.34 ± 6.20 was more tolerant than ellipsoidea 288.23 23.53 174.28 0.50 ml-1). a 72-hr chronic with glyphosate, decreased 400–500 ml-1 200–300 200–500 respectively. During 24-hr exposure maximum quantum photosystem II (Fv/Fm) as concentration increased. Overall, presented high positive correlation. It worthwhile mention our study provides detailed information sensitivity these glyphosate.