猪粪中3种四环素类抗生素在土壤中的动态变化及降解途径

采用室内模拟培养试验，研究了180 d内不同用量猪粪中3种四环素类抗生素（TCs）（包括四环素TTC，土霉素OTC，金霉素CTC）在土壤中降解的动态变化规律及降解途径。结果表明，猪粪中3种四环素类抗生素进入土壤后含量均呈现前期迅速下降，中后期减缓的规律，但不同种类和用量处理的变化速率和减少幅度有显著差异（P0.05）。180d时，猪粪处理土壤中的降解率为金霉素土霉素四环素，平均半衰期为17.43d、31.32d、49.48d。降解率与猪粪用量呈负相关，同培养时间呈正相关。猪粪中抗生素在土壤中的降解率要高于纯品抗生素，降解率的增加以外源微生物降解为主，外源微生物降解对四环素的作用最好。综上所述，随着培养时间的延长，猪粪中四环素类抗生素在土壤中能随微生物降解等作用而逐渐减少，但短期内仍可能产生环境危害。

Dynamics and mechanism of degradation of three tetracycline antibiotics from pig manures in soil

Simulated indoor incubation experiment was carried out to explore the degradation dynamics of three tetracycline antibiotics (TCs, including CTC, TTC and OTC) from pig manures in soil and the mechanisms were investigated as well. The results show that the TCs entering soil with pig manure can soon enter the degrading period, the three TCs concentrations of all the treatments are rapidly declined at the beginning, and after that the declining speeds are slowed down. The degradation rates and degradation percentages are significantly different for different antibiotics with different concentrations (P0.05). At the day of 180 the degradation percentages are in the order: CTCOTC TTC. The half lives of CTC, OTC and TTC are 17.43d, 31.32d and 49.48d. The degradation percentage is negatively correlated with the amount of manures used and positively correlated with incubation time. These results indicate that the TCs from pig manures in soil are more degradable than those of chemical ones. The microbiological from manures decomposition played an important role, the microorganic degradation is best for OTC. With the extension of incubation time, the concentrations of tetracycline antibiotics are declined through microbiological degradation and the others, but there may have the risk of environmental at a short time after the manures entering the soil.