摘要

       废水处理厂（WWTPs）中抗生素抗性基因的普遍存在和持续存在越来越引起人们的关注，剩余污泥是释放抗生素抗性基因（ARGs）的主要来源之一。此外，污泥中重金属的富集可能有利于ARGs和金属抗性基因（MRGs）的共同选择。需要对剩余污泥进行处理，以限制污水处理厂向环境中传播阻力。本研究旨在探讨嗜热两相（产酸/产甲烷相）厌氧消化过程中ARGs和MRGs的去向。利用种子数据库测定了流动遗传元素的发生率和丰度。在饲料污泥中检测到的27种主要ARG亚型中，产酸相（AP）使6种ARG亚型大幅度减少（50%），而63.0%的ARG亚型在随后的产甲烷相（MP）增殖。相比之下，AP中的MRG总丰度增加了2.8倍，而MP期间的MRG总丰度下降到与进料污泥相同的数量级。在两相厌氧消化过程中，ARGs和MRGs的动态变化是值得注意的，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%2Fs11356-018-1598-x