抗生素药物在不同环境介质中被频繁检出,其迁移分布特征和污染危害影响已引起相关研究人员的广泛关注。该研究从活性污泥中筛分出一株能够有效降解红霉素的菌株Ery-E,并对其降解特性和影响因素进行了分析讨论。根据菌株的菌落形态结构、生理生化特性,及其16S rDNA基因序列对比分析鉴定,菌株Ery-E属于恶臭假单胞菌(Pseudomonas putida)。该菌株能够以红霉素作为唯一碳源生存,最佳反应条件为:温度30℃、pH 7.0~7.5、初始红霉素投加浓度30 mg/L。在此条件下,菌株Ery-E对红霉素的5 d降解率可达76.6%。研究发现,红霉素的生物降解属于共代谢机制,外加碳源能够提高菌株Ery-E对红霉素的降解效果,当加入10 mg/L酵母粉时,菌株Ery-E对红霉素的5 d降解率可达83.9%。
Antibiotics have been frequently detected in environmental media and their transport behavior and contamination impacts are attracted worldwide attentions.A strain of erythromycin-degrading bacteria was isolated from activated sludge and denoted as Ery-E.Based on analysis of bacterial morphology,physiological-biochemical characteristics and 16S rDNA sequence,Ery-E was identified as Pseudomonas putida.The study demonstrated that Ery-E could survive using erythromycin as the sole carbon source.The optimum reaction conditions of 30℃,pH 7.0 ~7.5,initial concentration of erythromycin 30 mg/L would lead to erythromycin degradation rate for 5d as high as 76.6%.The biodegradation mechanism of erythromycin was confirmed as co-metabolism.Results indicated that the addition of extra carbon sources could enhance the biodegradation of erythromycin,which reached as high as 83.9% for 5d as the yeast powder was added at 10mg/L.