摘要

       污水处理厂 (WWTPs) 中抗生素抗性基因的普遍性和持续性越来越受到关注，残留污泥是抗生素抗性基因 (ARGs) 释放的主要来源之一。此外，浓缩污泥微生物群落中的重金属可能有利于 ARG 和金属抗性基因 (MRG) 的共同选择。需要对残留污泥进行处理，以限制污水处理厂的阻力向环境扩散。本研究旨在通过宏基因组分析探索在嗜热两相（产酸/产甲烷相）厌氧消化过程中 ARGs 和 MRGs 的命运。移动遗传元件的出现和丰度也是基于 SEED 数据库确定的。在进料污泥中检测到的 27 种主要 ARG 亚型中，产酸阶段 (AP) 实现了 6 种 ARG 亚型的大幅减少 (> 50%)，而 63.0% 的 ARG 亚型在随后的产甲烷阶段 (MP) 中增殖。相比之下，在 AP 中发现总 MRG 丰度增加了 2.8 倍，而 MP 期间的总丰度下降到与进料污泥相同的数量级。 ARGs 和 MRGs 在两阶段厌氧消化过程中的不同动态值得注意，需要更具体的处理来限制它们在环境中的增殖。

       The prevalence and persistence of antibiotic resistance genes in wastewater treatment plants (WWTPs) is of growing interest, and residual sludge is among the main sources for the release of antibiotic resistance genes (ARGs). Moreover, heavy metals concentrated in dense microbial communities of sludge could potentially favor co-selection of ARGs and metal resistance genes (MRGs). Residual sludge treatment is needed to limit the spread of resistance from WWTPs into the environment. This study aimed to explore the fate of ARGs and MRGs during thermophilic two-phase (acidogenic/methanogenic phase) anaerobic digestion by metagenomic analysis. The occurrence and abundance of mobile genetic elements were also determined based on the SEED database. Among the 27 major ARG subtypes detected in feed sludge, large reductions (> 50%) in 6 ARG subtypes were achieved by acidogenic phase (AP), while 63.0% of the ARG subtypes proliferated in the following methanogenic phase (MP). In contrast, a 2.8-fold increase in total MRG abundance was found in AP, while the total abundance during MP decreased to the same order of magnitude as in feed sludge. The distinct dynamics of ARGs and MRGs during the two-phase anaerobic digestion are noteworthy, and more specific treatments are required to limit their proliferation in the environment.

https://link.springer.com/article/10.1007/s11356-018-1598-x