| Butylated hydroxyanisole (BHA) and Norfloxacin (NFLX) are typicalpharmaceuticals used widely as feed additive and antibiotic agent in aquiculture. Theyalso affect the non-target organisms in the aquatic ecosystem while they are employedto act upon the target organisms in aquaculture. Chlorella pyrenoidosa andScenedesmus obliquus, Daphnia magna, Xiphophorus helleri are the representativeorganisms of phytoplankton, zooplankton and fish in aquatic ecosystem. The toxiceffects of these pharmaceuticals on Chlorella pyrenoidosa, Scenedesmus obliquus,Daphnia magna and Xiphophorus helleri were studied in the present study.The results showed that BHA was mid-toxic to Chlorella pyrenoidosa, whileNFLX was low-toxic. The 96h EC50 were 3.25 mg·L-1 and 31.35 mg·L-1, respectively,the security concentration was 0.33 mg·L-1 and 3.14 mg·L-1, respectively. Over the rangeof 0.5 mg·L-1 to 20 mg·L-1, an adaptive inducement phenomenon was observed onPhaseâ… metabolic enzyme (EROD) and Phaseâ…¡metabolic enzyme (e.g. GST and CAT)of Chlorella pyrenoidosa in BHA exposure. The same was for NFLX over the range of7.5 mg·L-1 to 120 mg·L-1. GST was strongly induced among all tested enzymes and CATwas induced remarkably, with a typical "bell" inducement curves. When theconcentration of NFLX was at 120 mg·L-1, CAT activity reached saturation, while noconspicuous effect was observed for activities of GSH. GST and CAT could act as thecandidate biomarkers of BHA and NFLX exposure to Chlorella pyrenoidosa.BHA and NFLX were mid-toxic and low-toxic to Scenedesmus obliquus,respectively, The 96 h EC50 was 6.19 mg·L-1 and 50.18 mg·L-1, respectively. Thesecurity concentration was 0.62 mg·L-1 and 5.02 mg·L-1, respectively. Over the range of1 mg·L-1 to 16 mg·L-1, an adaptive inducement phenomenon was observed on Phaseâ… metabolic enzyme (EROD) and Phaseâ…¡metabolic enzyme (e.g. GST and GSH) ofScenedesmus obliquus in BHA exposure. It was the same phenomena to NFLX over therange of 7.5 mg·L-1 to 120 mg·L-1. It was induced remarkably with the prolonging oftime. GST and EROD were induced significantly, and the activity of CAT was stronglyinduced in low concentration, and then inhibited gradually with the raising of BHA and NFLX level. While no conspicuous effects were exhibited for the activities of GSH. Thecontent of MDA showed typical "bell" curves in BHA exposure. When theconcentration of BHA reached 16 mg·L-1, MDA content was inclined to saturation. Thecontent of MDA was also induced in NFLX exposure. GST, CAT and EROD could actas the candidate biomarkers of BHA and NFLX exposure to Scenedesmus obliquus.It was mid-toxic for BHA to Daphnia magna and low-toxic for NFLX. The 48 hLC50 were 3.15 mg·L-1 and 194.98 mg·L-1 for BHA and NFLX, respectively. The safetyconcentration were 0.32 mg·L-1 and 19.50 mg·L-1, respectively.Over the range of 0.04 mg·L-1 to 3.75 mg·L-1, an adaptive inducement phenomenonwas observed on Phaseâ… metabolic enzyme (EROD) and Phaseâ…¡metabolic enzyme(GST) of Xiphophorus helleri in BHA exposure, and the activity of GST was stronglyinduced. It induced more remarkably with the extending of time. It was the samephenomena to NFLX over the range of 1mg·L-1 to 125 mg·L-1. The activity of CAT wasinhibited when the concentration of BHA was 3.75 mg·L-1 and NFLX was theconcentration of 125 mg·L-1. No significant effects were displayed for the content ofGSH and EROD in both BHA and NFLX exposure. When the concentration of BHAwas at 0.04 mg·L-1 and the concentration of NFLX was at 1 mg·L-1, the content of MDAwas declined lightly, and then increased gradually with the raising of concentration.GST and MDA could act as the candidate biomarkers of BHA and NFLX exposure toXiphophorus helleri. |
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