Sakaguchia cladiensis对磺胺甲嘧啶/铜复合污染中抗生素的降解

Biodegradation of Sulfamethazine in Sulfamethazine/Copper combined pollution by Sakaguchia cladiensis

以某畜禽养殖场土壤筛选分离到的一株对磺胺甲嘧啶(Sulfamethazine,SMZ)具有耐受性的酵母菌(Sakaguchia cladiensis,A5)为研究对象,开展生长特性及其对SMZ-Cu^2+复合污染中SMZ降解特性研究.结果表明,SMZ和Cu^2+胁迫下,菌A5也能较好生长.降解性能研究显示,菌A5在复合污染体系中反应3d,SMZ去除率达37.3%,共存的Cu^2+对SMZ降解具有促进作用.当投菌量为1g/L,溶液pH值为中性,菌A5对1mg/L SMZ的降解效果最佳.透射电镜分析表明,SMZ和Cu^2+共存时,菌A5的细胞壁膜破损严重,导致细胞质外流.

To understand the characteristics of sulfamethazine(SMZ)biodegradation in the polluted environment where SMZ and Cu^2+co-existed,this study focused on the bio-treatment of SMZ-Cu^2+in different conditions by Sakaguchia cladiensis(named A5),a strain resistant to sulfamethazine,which was screened and isolated from the soil of a livestock and poultry farm(Guangzhou,China).The results showed that,with the presence of single SMZ or SMZ-Cu^2+combined pollution in the culture medium,strain A5 still maintained a good growth trend.Sakaguchia cladiensis was an effective strain to remove SMZ from pollution system.The presence of Cu^2+was beneficial for A5 to decompose SMZ.The degradation rates of SMZ reached 37.3%in 3 d.Under the condition of 1 g/L of inoculum,lmg/L initial concentration of SMZ,and neutral pH,the removal effect of strain A5 on SMZ was the best.The transmission electron microscope(TEM)analysis showed that the cells of strain A5 were severely damaged when SMZ and Cu^2+co-existed in solution,leading to the outflow of cytoplasm.