摘要
      灰水（GW）中的线性烷基苯磺酸钠（LAS）将模拟基于生物膜的系统中抗生素抗性基因（ARGs）的产生。我们的研究强调了氧基膜生物膜反应器（O2-MBfR）处理GW中溶解氧（DO）依赖性ARGs的积累和微生物生态位的演替，并揭示了EPS的关键作用。DO浓度的变化导致ARGs产生、EPS分泌和微生物群落以及有机物和氮去除效率的显著差异。DO浓度从0.2 mg/L增加到0.4 mg/L，导致有机物（>90%）和氮去除率提高，生物膜中的EPS（尤其是蛋白质和碳水化合物）和ARGs积累（如intI-1、korB和sul-2）减少；LEfSe分析显示，高DO浓度积累的微生物生态位，包括黄杆菌科和蓝藻，有助于氮还原和有机物的生物降解。而在低DO条件下（0.2mg/L），低效的电子受体降低了有机物和氮的去除效率，并改善了EPS在生物膜中的积累；高EPS能够从液相中捕获残留的LAS，这通过不同的微生物群落组成刺激了ARGs的产生。这些发现提示了在O2 MBfR治疗GW中基于DO的ARGs减少调节策略。
Abstract
Linear alkylbenzene sulfonates (LAS) in greywater (GW) will simulate antibiotic resistance genes (ARGs) production in the biofilm-based system. Our study emphasizes the dissolved oxygen (DO)-dependent ARGs accumulation and microbial niches succession in an oxygen-based membrane biofilm reactor (O2-MBfR) treating GW, as well as revealing the key roles of EPS. Changing DO concentrations led to significant differences in ARGs production, EPS secretion and microbial communities, as well as the organics and nitrogen removal efficiency. Increasing DO concentration from 0.2 to 0.4 mg/L led to improved organics (> 90%) and nitrogen removal, as well as less EPS (especially for proteins and carbohydrates) and ARGs accumulation (e.g., intI-1, korB and sul-2) in the biofilm; the high-DO-concentration accumulated microbial niches, including Flavobacteriaceae and Cyanobacteria that revealed by LEfSe analysis, contributed to both nitrogen reduction and organics biodegradation. While, the inefficient electron acceptor at low DO conditions (0.2 mg/L) reduced the organics and nitrogen removal efficiency, as well as the improved accumulation of EPS in biofilm; high EPS enabled the capture of residual LAS from the liquid phase, which stimulated the production of ARGs by the distinct microbial community compositions. These findings suggested the DO-based ARGs reduction regulation strategy in the O2-MBfR treating GW.

https://www.sciencedirect.com/science/article/abs/pii/S0048969722021556