发布者:抗性基因网 时间:2023-05-29 浏览量:199
摘要
海水养殖部门广泛使用抗生素,导致大量抗生素残留。因此,海水养殖废水迫切需要在排放前进行处理。本研究采用缺氧/好氧移动床生物膜反应器(A/O-MBBR)处理海水养殖废水中的磺胺甲恶唑(SMX),研究了SMX的去除机理和抗生素抗性基因(ARGs)的变异。结果表明,生物反应器去除了22%-33%的SMX,其中少量SMX被细胞外聚合物吸附和储存,大部分SMX(>80%)在缺氧池中被生物降解。缺氧条件下硝酸盐的存在有利于SMX的降解。假单胞菌、脱硫菌和甲烷菌物种以及微生物过氧化氢酶对SMX的生物转化有贡献。ARGs(sul1、sul2和int1)和mRNA(sul1和sul2)的定量PCR分析表明,SMX富集了SMX相关的ARGs,并增强了相应基因的表达。大部分ARG最终与污水一起排放。因此,基于生物工艺处理海水养殖废水的出水中仍然含有抗生素残留和抗性基因,应通过适当的技术进一步控制。
Abstract
Antibiotics are widely dosed in mariculture sector, resulting in substantial antibiotics residues. Hence, mariculture wastewater is urgent to be treated before discharging. In this study, the anoxic/oxic moving bed biofilm reactor (A/O-MBBR) was used to treat the wastewater containing sulfamethoxazole (SMX) from mariculture, SMX removal mechanism and the variation of antibiotic-resistant genes (ARGs) were investigated. The results showed that 22%–33% of SMX was removed by the bioreactor, where a small amount of SMX was adsorbed and stored by the extracellular polymers and most of SMX (>80%) was biodegraded in the anoxic tank. Occurrence of nitrate in anoxic condition was conducive to SMX degradation. Pseudomonas, Desulfuromusa, and Methanolobus species, as well as microbial catalase contributed to the SMX biotransformation. Quantitative PCR analysis of ARGs (sul1, sul2 and int1) and mRNA (sul1, sul2) showed that SMX enriched SMX-related ARGs and enhanced the expression of corresponding genes. Most of ARGs finally were discharged with effluent. Hence, the effluent from biologically based processes treating mariculture wastewater still contained antibiotics residue and resistance genes, which should be further controlled by suitable techniques.
https://www.sciencedirect.com/science/article/abs/pii/S0045653522008207