Change in microbial community in landfill refuse contaminated with antibiotics facilitates denitrification more than the increase in ARG over long-term.
Change in microbial community in landfill refuse contaminated with antibiotics facilitates denitrification more than the increase in ARG over long-term.
复制标题
长期来看，受抗生素污染的垃圾填埋场垃圾中微生物群落的变化比 ARG 的增加更能促进反硝化
DOI：
10.1038/srep41230
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发表时间：
2017-01-25
影响因子：
4.6
通讯作者：
Xie B
中科院分区：
文献类型：
--
作者：
Wu D;Chen G;Zhang X;Yang K;Xie B
在这项研究中，向垃圾填埋场垃圾中添加磺胺二甲嗪（SMT）将氮中间体（例如N2O和NO）和二氮（N2）气体通量降低至<0.5 μg-N/kg-refuse·h−1，而在土霉素样品中，N2O和N2通量分别为~1.5和5.0 μg-N/kg-refuse·h−1 （OTC）已被添加。长期接触抗生素后，垃圾中的 ARG（抗生素抗性基因）水平增加了 10 倍，随后 N2 通量增加了四倍，但具有最大抗性组的 SMT 修改样品促进反硝化的程度（氮以 NO 气体形式积累，约为 6 μg-N/kg-refuse·h−1），其程度低于 OTC 修改样品。此外，深度测序结果表明，长期OTC暴露部分取代了Hyphomicrobium、Fulvivirga和Caldilinea (>5%)，以取代含有与氮排放模式显着相关的nosZ和norB基因的优势细菌宿主(Rhodothermus，约20%)，而磺胺二甲嗪改良剂完全降低了产生NOx气体还原作用的“原始居民”的相对丰度。在 SMT 组中大量富集的主要 ARG 载体（假单胞菌）具有较低水平的反硝化功能基因，这可能意味着反硝化更多地受到细菌动态的影响，而不是抗生素压力下 ARG 丰度的影响。
In this study, the addition of sulfamethazine (SMT) to landfill refuse decreased nitrogen intermediates (e.g. N2O and NO) and dinitrogen (N2) gas fluxes to <0.5 μg-N/kg-refuse·h−1, while the N2O and N2 flux were at ~1.5 and 5.0 μg-N/kg-refuse·h−1 respectively in samples to which oxytetracycline (OTC) had been added. The ARG (antibiotic resistance gene) levels in the refuse increased tenfold after long-term exposure to antibiotics, followed by a fourfold increase in the N2 flux, but SMT-amended samples with the largest resistome facilitated the denitrification (the nitrogen accumulated as NO gas at ~6 μg-N/kg-refuse·h−1) to a lesser extent than OTC-amended samples. Further, deep sequencing results show that long-term OTC exposure partially substituted Hyphomicrobium, Fulvivirga, and Caldilinea (>5%) for the dominant bacterial hosts (Rhodothermus, ~20%) harboring nosZ and norB genes that significantly correlated with nitrogen emission pattern, while sulfamethazine amendment completely reduced the relative abundance of the “original inhabitants” functioning to produce NOx gas reduction. The main ARG carriers (Pseudomonas) that were substantially enriched in the SMT group had lower levels of denitrifying functional genes, which could imply that denitrification is influenced more by bacterial dynamics than by abundance of ARGs under antibiotic pressures.