制药废水受纳河流中四环素抗药基因及微生物群落结构变化研究

Changes of tetracycline resistance genes and microbial community structure in a river receiving pharmaceutical production wastewater

考察了含有土霉素制药废水的污水处理厂排放在冬季和夏季对受纳河流中四环素抗药基因及微生物群落结构的影响.利用PCR方法,对该河流中16种四环素抗药基因(TRGs)进行了检测,其中6种在排放口及下游被检出.通过Real-timePCR对其中的3种抗药基因(tet(L)、tet(W)和tet(X))及总细菌的16SrRNA基因进行定量分析(TRGs/16SrRNA基因),结果表明:tet(L)、tet(W)和tet(X)与16SrRNA基因的比值在排放口和下游(3.34×10-3～2.38×10-1)显著高于排放口上游(1.16×10-5～2.38×10-2),表明污水排放造成了抗药基因的增加.夏季河水中TRGs/16SrRNA基因明显低于冬季.利用PCR-DGGE对不同河流沉积物中微生物群落结构进行了研究,结果表明,污水的排放显著改变了河流中的微生物群落结构,一些代表性TRGs宿主细菌的条带在排放点和河流下游明显增加.

Changes of tetracycline resistance genes and microbial community structure were investigated in a river receiving treated municipal wastewater containing oxytetracycline production waste streams.Among the sixteen tetracycline resistance genes（TRGs）studied,six TRGs were detected at the discharge site and downstream in the river.Real-time PCR results show that the abundance of three TRGs（tet（L）、tet（W）and tet（X））normalized to 16S rRNA genes（TRGs/16S rRNA genes）increased at the discharge site and downstream（from 3.34×10-3 to 2.38×10-1）,compared to the TRGs/16S rRNA genes in upriver samples（from 1.16×10-5 to 2.38×10-2）,which suggested that wastewater discharge affected the distribution of TRGs in the receiving river.The values of TRGs/16S rRNA genes in summer were lower than those in winter.At the same time,a remarkable change of the microbial community structures in the river sediments was found before and after wastewater discharge.According to PCR-DGGE analysis,bands of TRG host bacteria increased at both the discharge and downstream sites.