Figuring out the comprehensive metabolic mechanism of sulfonamide antibiotics (SA) is critical to improve and optimize SA removal in the bioremediation process, but relevant studies are still lacking. Here, an approach integrating metagenomic analysis, degraders’ isolation, reverse transcriptional quantification and targeted metabolite determination was used to decipher microbial interactions and functional genes’ characteristics in SA-degrading microbial consortia enriched from wetland sediments. The SA-degrading consortia could rapidly catalyze ipso-hydroxylation and subsequent reactions of SA to achieve the complete mineralization of sulfadiazine and partial mineralization of the other two typical SA (sulfamethoxazole and sulfamethazine). Paenarthrobacter, Achromobacter, Pseudomonas and Methylobacterium were identified as the primary participants for the initial transformation of SA. Among them, Methylobacterium could metabolize the heterocyclic intermediate of sulfadiazine (2-aminopyrimidine), and the owning of sadABC genes (SA degradation genes) made Paenarthrobacter have relatively higher SA-degrading activity. Besides, the coexistence of sadABC genes and sul1 gene (SA resistance gene) gave Paenarthrobacter a dual resistance mechanism to SA. The results of reverse transcription quantification further demonstrated that the activity of sadA gene was related to the biodegradation of SA. Additionally, sadABC genes were relatively conserved in a few Microbacteriaceae and Micrococcaceae SA-degraders, but the multiple recombination events caused by densely nested transposase encoding genes resulted in the differential sequence of sadAB genes in Paenarthrobacter genome. These new findings provide valuable information for the selection and construction of engineered microbiomes.

弄清磺胺类抗生素（SA）的综合代谢机制对于提高和优化生物修复过程中SA的去除至关重要，但仍缺乏相关研究。在这里，一种结合宏基因组分析、降解者分离、逆转录定量和靶向代谢物测定的方法被用来破译从湿地沉积物中富集的 SA 降解微生物群落中的微生物相互作用和功能基因的特征。SA降解聚生体可以快速催化SA的自身羟基化和后续反应，以实现磺胺嘧啶的完全矿化和其他两种典型SA（磺胺甲恶唑和磺胺二甲嘧啶）的部分矿化。拟节杆菌属、无色杆菌属、假单胞菌属和甲基杆菌被确定为 SA 初始转化的主要参与者。其中，甲基杆菌能够代谢杂环中间体磺胺嘧啶（2-氨基嘧啶），而sadABC基因（SA降解基因）的拥有使得Paenarthrobacter具有相对较高的SA降解活性。此外， sadABC基因和sul1基因（SA抗性基因）的共存，赋予了Paenarthrobacter对SA的双重抗性机制。逆转录定量结果进一步证明sadA基因的活性与SA的生物降解有关。此外，sadABC基因在少数微杆菌科和微球菌科 SA 降解菌中相对保守，但由密集嵌套的转座酶编码基因引起的多次重组事件导致sadAB基因在Paenarthrobacter基因组中的差异序列。这些新发现为工程微生物组的选择和构建提供了有价值的信息。