摘要
      释放到环境中的抗生素耐药性基因（ARGs）是一个新出现的人类和环境健康问题，包括在废水处理废水中传播的ARGs。在中低收入国家（LMIC），替代传统系统的另一种废水处理选择是使用微藻细菌聚集体（MABA）进行废物降解的低能耗、高速率藻类池塘（HRAP）。在这里，我们研究了在基于MABA的中试规模室外系统中连续运行140天的ARG去除的稳健性。HRAP系统成功地去除了73%至88%的化学需氧量和高达97.4%的氨，骨料尺寸随着操作时间的推移而增加。使用宏基因组学在HRAP进水、MABA和出水中鉴定出14种ARG类别，HRAP过程将进水到出水的总ARG丰度降低了5倍。平行qPCR分析显示，HRAP系统显著降低了样本ARG（p<0.05），sul1、tetQ、blaKPC和intl1基因的对数去除率分别为1.2至4.9、2.7至6.3、0至1.5和1.2至4.8。进水、出水和MABA样品的测序显示，相关的微生物群落存在显著差异，其中肠杆菌类（临床相关的携带ARGs的细菌）的进水群落在MABA和出水中不太明显。从这个意义上说，这类细菌可能被排除在MABA之外，因为它们具有良好的沉降特性和抗菌肽的存在。微藻细菌处理系统在运行期间稳定地减少了废水中的ARG，利用阳光作为能量驱动，使其成为LMIC废水处理应用的理想选择。
Abstract
Antibiotic resistance genes (ARGs) released into the environment are an emerging human and environmental health concern, including ARGs spread in wastewater treatment effluents. In low-to-middle income countries (LMICs), an alternate wastewater treatment option instead of conventional systems are low-energy, high-rate algal ponds (HRAP) that use microalgae-bacteria aggregates (MABA) for waste degradation. Here we studied the robustness of ARG removal in MABA-based pilot-scale outdoor systems for 140 days of continuous operation. The HRAP system successfully removed 73 to 88 % chemical oxygen demand and up to 97.4 % ammonia, with aggregate size increasing over operating time. Fourteen ARG classes were identified in the HRAP influent, MABA, and effluent using metagenomics, with the HRAP process reducing total ARG abundances by up to 5-fold from influent to effluent. Parallel qPCR analyses showed the HRAP system significantly reduced exemplar ARGs (p < 0.05), with 1.2 to 4.9, 2.7 to 6.3, 0 to 1.5, and 1.2 to 4.8 log-removals for sul1, tetQ, blaKPC, and intl1 genes, respectively. Sequencing of influent, effluent and MABAs samples showed associated microbial communities differed significantly, with influent communities by Enterobacteriales (clinically relevant ARGs carrying bacteria), which were less evident in MABA and effluent. In this sense, such bacteria might be excluded from MABA due to their good settling properties and the presence of antimicrobial peptides. Microalgae-bacteria treatment systems steadily reduced ARGs from wastewater during operation time, using sunlight as the energetic driver, making them ideal for use in LMIC wastewater treatment applications.

https://www.sciencedirect.com/science/article/abs/pii/S0048969723021642