中文摘要：

为了解抗生素对环境污染物高效降解菌的生态效应,通过红霉素对菲高效降解菌GY2B的毒性实验以及抗生素后效应（PAE）的测定,研究了菌体细胞在红霉素作用下的生理、毒理指标以及后效应期间菌体的变化。结果表明,GY2B对红霉素的最高耐受（99.9%死亡率）浓度为25μg/mL,长期接触低于25μg/mL的红霉素可降低GY2B对药物敏感性,使其产生耐药性;当红霉素浓度高于最低抑菌浓度（0.25μg/mL）时,能显著降低菌体细胞的总超氧化物歧化酶（SOD）活力,引起活性氧对菌体的损伤,亦能显著降低乳酸脱氢酶（LDH）活力,但对菌体细胞有氧呼吸水平的影响会随着时间逐渐减弱;GY2B在短暂接触红霉素后2~3 h即可复苏生长（菌密度增加10倍）,但红霉素能对GY2B产生明显的后效应,诱发细胞SOS修复机制和自溶现象,使得DNA含量发生显著变化。因此,环境中抗生素对污染物降解微生物的生态效应值得关注。

英文摘要：

To understand the ecological effects of antibiotics on efficient environmental pollutant degrading bacteria,the toxicity test of erythromycin on efficient phenanthrene-degrading bacteria GY2B and the determination of post-antibiotic effect（ PAE） were performed. Some physiological and toxicological indexes of erythromycin on GY2B were studied,as well as the bacterial changes during the period of PAE. The results revealed that the maximum tolerant concentration（ 99. 9% mortality） of GY2B to erythromycin was 25 μg/mL,long-term exposure to erythromycin（ 25 μg/mL） could decrease the sensitivity of GY2B and induce the drug resistance. When concentration of erythromycin was higher than minimal inhibitory concentration（ 0. 25 μg/mL）,it reduced significantly the total superoxide dismutase activity（ SOD） of the cell,did damage to the bacteria by active oxygen and decreased the activity of lactate dehydrogenase（ LDH）,though the effect on the level of oxygen breathing would be weakened gradually. GY2B cells were able to recover in short exposure to erythromycin 2 ~ 3 h（ the bacterial density increased 10 times）,but erythromycin had significant PAE on GY2B,induced SOS repair mechanisms as well as autolysis and made a large DNA content change. As a result,the ecological effects of antibiotics on the pollutants degrading microorganisms in the environment should not be overlooked.