Campos J L, Garrido J M, Méndez R, Lema J M
Chemical Engineering Department, University of Santiago de Compostela, Galiza, Spain.
Appl Biochem Biotechnol. 2001 Jul;95(1):1-10. doi: 10.1385/abab:95:1:01.
The effects of two broad-spectrum antibiotics, chloramphenicol and oxytetracycline hydrochloride, on the microbial activity and biofilm stability of a mixed nitrifying culture were studied. These antibiotics are present in some wastewaters generated in cattle farms or pharmaceutical industries. A 1-L fermentor, in which nitrifiers grew both in suspension and in a biofilm, was used during the experiments. Chloramphenicol (10-250 mg/L) barely had any effect on biofilm stability and nitrification. Ammonia was fully oxidized to nitrate. However, oxytetracycline caused biofilm sloughing at concentrations of 10 mg/L, but nitrification was not inhibited at antibiotic concentrations up to 100 mg/L. When the concentration of oxytetracycline chlorohydrate was increased stepwise from 100 to 250 mg/L, nitrification was inhibited by 50%. The dissolved organic carbon measurements in both the influent and effluent showed that the antibiotics were neither mineralized by the mixed nitrifying culture nor accumulated in the system. Furthermore, the microbial tests did not reveal the presence of active antibiotics in the effluent. This fact indicates that both cloramphenicol and oxytetracycline were degraded by the nitrifying sludge but not mineralized.
研究了两种广谱抗生素，即氯霉素和盐酸土霉素，对混合硝化培养物的微生物活性和生物膜稳定性的影响。这些抗生素存在于一些养牛场或制药行业产生的废水中。实验期间使用了一个1升的发酵罐，硝化菌在其中以悬浮状态和生物膜状态生长。氯霉素（10 - 250毫克/升）对生物膜稳定性和硝化作用几乎没有任何影响。氨被完全氧化为硝酸盐。然而，土霉素在浓度为10毫克/升时会导致生物膜脱落，但在抗生素浓度高达100毫克/升时硝化作用并未受到抑制。当盐酸土霉素的浓度从100毫克/升逐步增加到250毫克/升时，硝化作用受到50%的抑制。进水和出水的溶解有机碳测量结果表明，这些抗生素既没有被混合硝化培养物矿化，也没有在系统中积累。此外，微生物测试未发现出水中存在活性抗生素。这一事实表明，氯霉素和土霉素均被硝化污泥降解但未被矿化。
