Transportation And Transformation Of Chloramphenicol In Coastal Environment

Antibacterial chemotherapy is applied in aquaculture throughout the world. Bacterial disease occurs most frequently and severely in intensive culture systems and it is there that most antibacterials are used. Because of the lack of scientific guidelines, antibiotic abuse is a severe problem in China, causing coastal ecological environment pollution. People pay more attention to disease prevention and increasing production, but environmental problems arising from the use of antibiotics are often ignored. In order to evaluate persistence of chloramphenicol, transportation and transformation mechanisms of chloramphenicol in marine environment were studied. The main conclusions obtained were listed as follows:The study of chloramphenicol photolysis and hydrolysis in seawater demonstrated that, ultraviolet absorption bands of chloramphenicol were the same in different medium solutions, and salinities had little effect on the degradation of it. Besides, the photolysis and hydrolysis rates were strongly influenced by pH.The study of chloramphenicol degradation in sediment demonstrated that degradation process fitted well to the decaying exponential curve. Sediment organic matter, microbial status and initial concentration could obviously affect chloramphenicol degradation in sediment. In conclusion, the differences in degradation rates among various conditions were attributed to the effects of microbial activities under different environments. Besides, the degradation half-life in anaerobic sediment was more than that in aerobic sediment.The bioaccumulation and elimination of chloramphenicol in different tissues of Ruditapes philippinarum (Adams et Reeve) had been studied. The test was performed under semi-static conditions. Firstly, a high performance liquid chromatography method had been developed for determination of chloramphenicol in tissues of Ruditapes philippinarum. The detection limit was 6.0μg/kg and the recoveries of samples were 85.25%~85.46%. Secondly, the results showed that the Ruditapes philippinarum had low ability to accumulate chloramphenicol in aquatic system, and bioaccumulation factors were low (maximum: 1.8 for chloramphenicol in muscle and viscera). Theaccumulating quantity in Ruditapes philippinarum was different in the diverse concentration in the water, and the higher concentration had the greater accumulating quantity at the same time. The accumulation of chloramphenicol increased by time, and reached the balance in 6~8d. The accumulation and elimination of chloramphenicol in muscle were slower as compared with viscera.