Abstract: “Microalgae are widespread organisms which can be used as bioindicator for pesticides in water. The inhibition of photosynthesis by pesticides, which leads to the change in fluorescence emission can be used as the parameter of detection. In this study, the responses of microalgae Chlorella vulgaris to two pesticides- atrazine and 2,4-dichlorophenoxyacetic acid (2,4-D) were reported. For the optimized responses, C. vulgaris from day-3 culture with approximate 3.5 x 106 cells was immobilized with 0.5 % of agarose, which later exposed to different concentrations of atrazine and 2,4-D for 15 minutes respectively. The results showed C. vulgaris responded to both pesticides from the range of 0.001 mg/L – 10.000 mg/L. The results confirmed the potential of C. vulgaris as bioindicator for both pesticides”

Keywords: Heavy metals indicator, Anabaena cylindrica, Carotenoids