Laboratorio de Investigación en Procesos Avanzados de Tratamiento de Aguas, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico.
School of Engineering, Newcastle University, Cassie Building, Newcastle upon Tyne NE1 7RU, UK.
Sci Total Environ. 2023 Jul 15;882:163545. doi: 10.1016/j.scitotenv.2023.163545. Epub 2023 Apr 18.
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, bla, 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.
抗生素耐药基因 (ARGs) 释放到环境中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 (LMICs)，替代传统系统的废水处理选择是低能量、高速率藻类池塘 (HRAP)，该系统使用微藻-细菌聚集体 (MABA) 进行废物降解。在这里，我们研究了基于 MABA 的中试规模室外系统在 140 天连续运行过程中去除 ARG 的稳健性。HRAP 系统成功去除了 73%至 88%的化学需氧量和高达 97.4%的氨，随着运行时间的增加，聚集体的尺寸也在增加。使用宏基因组学在 HRAP 进水、MABA 和出水中共鉴定出 14 种 ARG 类，HRAP 工艺将总 ARG 丰度从进水降低到出水减少了多达 5 倍。平行 qPCR 分析表明，HRAP 系统显著降低了典型的 ARGs (p<0.05)，sul1、tetQ、bla 和 intl1 基因的去除率分别为 1.2 到 4.9、2.7 到 6.3、0 到 1.5 和 1.2 到 4.8 log。进水、出水和 MABAs 样品的测序表明，相关微生物群落差异显著，进水群落为肠杆菌目（携带临床相关 ARGs 的细菌），而在 MABA 和出水群落中则不明显。从这个意义上说，由于良好的沉降特性和抗菌肽的存在，这些细菌可能会被排除在 MABA 之外。微藻-细菌处理系统在运行过程中使用阳光作为能量驱动，从废水中稳定地去除 ARGs，使其成为在 LMIC 废水处理应用中的理想选择。
