Effects Of Three Kinds Of Endocrine Disrupting Chemicals On The Growth And Physiology Of Microcystis Aeruginosa

Endocrine disrupting chemicals (EDCs) are widely found in bothnon-biosphere and biosphere. They travel among water, air and soil throughsurface runoff, rainfall, adsorption and permeation. EDCs get enrichment andpass on in the food chain when they are in the living bodies. It is reported thatEDCs exist in lakes, rivers and ground water of many countries. They doharm to genital system, endocrinium and nervous system of humans andanimals. What was worse, they may lead to cancer. EDCs have drawn globalattention. Bisphenol A (BPA), N-nonylphenol (4-NP) and17β-estradiol aretypical EDCs and closely linked to daily life. Microcystis aeruginosa has awide distribution in eutrophic water of China, especially in Taihu Lake,Chaohu Lake and Dianchi Lake. In this study, biomass of alga, concentrationof Chlorophyll a, MDA and soluble protein, Fv/Fm and SOD activity weredetected to characterize the BPA’s,4-NP’s and E2’s effect on M. aeruginosa.Meanwhile, three proportions (1:4,1:1,4:1) were set to study the jointtoxicity of BPA,4-NP and E2on M. aeruginosa. This can be helpful toevaluate the risk of EDCs. Besides, the removal of BPA,4-NP and E2by M.aeruginosa were also detected.The results show that:(1) BPA,4-NP and E2presented a trend ofpromotion in low concentration and inhibition in high concentration on M.aeruginosa.0.5mg/L BPA and0.5mg/L E2enhanced the biomass of alga.The higher concentration, the more harmful they did to M. aeruginosa.(2)BPA,4-NP and E2hurt the membrane, so that the permeability and content ofMDA rose. So did the SOD activity.(3) Under similar concentration,4-NPpresented maximum inhibition of alga. BPA did the minimum inhibition ofbiomass, but the maximum of Chl a. E2had the lightest effect on photosystem.(4) The7d-EC50of BPA,4-NP and E2were19.355mg/L,3.113mg/L and11.756mg/L. The toxicity of4-NP was6.2times than BPA and3.8times than E2with the same mass.(5) In the joint toxicity experiment, B1E4,B1E1and B4E1showed synergistic effect, partial additive effect andsynergistic effect, respectively. B1E4was stronger than B4E1. N1E4, N1E1and N4E1showed antagonism effect, partial additive effect and synergisticeffect, respectively.(6) The effect on alga’s growth and physiology was inagreement with the results of the joint toxicity effect evaluation.(7) M.aeruginosa played an enrichment role on BPA,4-NP and E2. The enrichmentof BPA and4-NP went up as their initial concentration increased.