Study On Biological Toxicity Of Antibiotic Wastewater And Bacteria Residue To Fish

Large quantity of antibiotic wastewater was discharged and large amount of antibioticbacteria residue was produced in the process of antibiotic production. They maybe pose agreat risk and the potential impact for aquaorganisms difficult to predict bybioconcentration, the food chain and other sectors. The effects of antibiotic wastewater（effluent of penicillin and oxytetracycline, influent and effluent of streptomycin） andantibiotic bacteria residue on Zebrafish and Cyprinus carpio were measured byconsidering a number of parameters including antioxidant enzyme activities and lipidperoxidation. The main research results are as follows:The96h LC₅₀values of the effluent of penicillin and oxytetracycline to Zebrafish andCyprinus carpio is11.01%and12.96%, respectively.Exposure to effluent of penicillin and oxytetracycline at different concentrations,SOD activity, MDA content in Zebrafish muscle showed decrease-increase-decrease law.Exposure to1/496h LC₅₀group, SOD activity was inhibited significantly at4d （P<0.01）.Exposed to1/1696h LC₅₀group, MDA content was higher significantly than control at8d（P<0.01）. Both SOD and CAT levels in Cyprinus carpio liver first increased and thendecreased. SOD activity induced significantly （0.01<P<0.05） at8d, meanwhile CATactivity inhibited significantly at10d （0.01<P<0.05） when Cyprinus carpio exposed to1/496h LC₅₀.POD level in Cyprinus carpio gill first decreased and then increased and MDAcontent in Cyprinus carpio showed increase-decrease-increase law. MDA content washigher significantly（P <0.01） than control at4d and10d,meanwhile POD level inhibitedsignificantly（0.01<P<0.05） at6d exposed to1/496h LC₅₀. Therefore, SOD and MDAlevel were the more sensitive masured parameters and may be used as potentialbiomarkers for effluent of penicillin and oxytetracycline exposure.The96h LC₅₀values of the influent of streptomycin to Zebrafish and Cyprinus carpiois27.53%and41.45%, respectively.SOD activity, POD activity and MDA content in Zebrafish muscle showed decrease-increase-decrease law when the fish was exposed to the influent of streptomycin. SOD andPOD levels were inhibited significantly （0.01<P<0.05）, MDA content was highersignificantly than control （0.01<P<0.05） at15d at an exposure level of1/296h LC₅₀. SODactivity of Cyprinus carpio liver showed increase-decrease-increase-decrease law. Uponexposure to1/296h LC₅₀, SOD activity was inhibited significantly at24d and28d （P<0.01）. POD activity in Cyprinus carpio gill showed increase-decrease-increase-decrease law and MDA content first decreased and then increased and decreasedat last. POD level induced significantly （0.01<P<0.05） at12d and16d and MDA contentwas higher significantly （0.01<P<0.05） than control at20d, which indicate the fish areexposed to polluted waterbody and the body was damaged.SOD and POD activity in Zebrafish muscle inhibited significantly （0.01<P<0.05） at96h at an exposure level of100%and inhibited more with the concentration increasingexposing to the effluent of streptomycin. Compared with the control group, MDA contentwas significantly lower for each concentration group （0.01<P<0.05）. SOD and CAT levelsin Cyprinus carpio gill were induced significantly （P<0.01） while inhibited more with itsconcentration increasing. POD activity was induced but it decreased with its concentrationincreasing. T-AOC level was lower significantly than control （P<0.01）, which means itdecrease. MDA content was significantly higher than control （0.01<P<0.05）. Therefore,SOD and MDA were the more sensitive parameters and may be used as potentialbiomarkers for the influent of streptomycin exposure.No death when Zebrafish exposed to100%supernatant of streptomycin bacteriaresidue after96h, which showed that there was not acute toxicity for it to zebrafish.SOD acticity and POD activity in Zebrafish muscle showed decrease-increase-decrease law exposing to the supernatant of streptomycin bacteria residue, whileMDA content in Zebrafish muscle showed increase-decrease-increase-decrease law. Uponexposure to50%, SOD activity was inhibited significantly at9d and12d （0.01<P<0.05）,which mean the fish was damaged and the lipid peroxidation was produced. Therefore,SOD and MDA were the more sensitive parameters and may be used as potentialbiomarkers for the influent of streptomycin exposure.