MBR工艺处理螺旋霉素制药废水过程中抗生素耐药菌与抗性基因的研究

抗生素废水含有大量的抗生素耐药菌(antibiotic resistant bacteria,ARB)与抗性基因(antibiotic resistance genes,ARGs),处理排放后可能增强受纳环境的微生物抗性,因此有必要深入研究抗生素废水处理过程中ARB与ARGs的削减效果及其影响因素。本研究采用膜生物反应器(membrane bioreactor,MBR)工艺处理螺旋霉素制药废水,考察了不同水力停留时间(hydraulic retention time,HRT)对ARB与ARGs削减效果的影响。结果表明,虽然在HRT=30 h时MBR对COD与氨氮的去除率略高于HRT=40 h,但HRT=40 h时,不仅总异养菌与肠球菌的去除效果更佳,出水肠球菌耐药率及携带的抗性基因检出率也更低,而且MBR对废水中erm B、erm F、erm X、mef A、ere A、mph B和转移元件ISCR 1、Tn 916/1545相对丰度的削减效果更好。这表明长HRT更有利于MBR工艺削减螺旋霉素废水的耐药菌与抗性基因。

Reduction of Antibiotic Resistant Bacteria and Genes in Spiramycin Wastewater Treated by Membrane Bioreactor (MBR) Process

Antibiotics production wastewater contains large amounts of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs), and the treated wastewater would improve the antibiotic resistance of the environmental bacteria. It is necessary to investigate the reduction of ARB and ARGs during the treatment of antibiotics production wastewater. In this study, the spiramycin production wastewater was treated by membrane bioreactor (MBR), and the removal of ARB and ARGs under two hydraulic retention times (HRT) were investigated. The results revealed that the COD and NH₄⁺-N removal performances were slightly higher at HRT 30 h than at 40 h, however, the removals of total heterotrophic bacteria and enterococci were better at HRT 40 h, as well as the antibiotic resistance rate of enterococci, and the detection of ARGs carried by enterococci were lower at HRT 40 h. Furthermore, the relative abundances of ARGs (ermB, ermF, ermX, mefA, ereA and mphB) and mobile elements (ISCR1 and Tn916/1545) were reduced more at HRT 40 h than at 30 h. These results indicated that longer HRT for MBR treating spiramycin wastewater would achieve better removal efficiencies of the ARB and ARGs.