摘要

       蚯蚓堆肥是一种利用蚯蚓和微生物的共同作用，用于污水污泥回收利用的绿色技术。尽管四环素在污水污泥中含量丰富，但很少有人关注它对蚯蚓粪的影响。本研究调查了不同四环素浓度（0、100、500 和 1000mg/kg）对掺入污泥的蚯蚓堆肥过程中有机物分解、微生物群落和抗生素抗性基因 (ARG) 的影响。结果表明，100mg/kg的四环素可以刺激蚯蚓的生长，同时污泥中有机物的腐殖化和分解率最高。活性微生物细胞的丰度和多样性随着四环素浓度的增加而降低。拟杆菌属成员在四环素加标处理中占主导地位，尤其是在高浓度处理中。与其对应物相比，四环素的添加显着增加了 ARG（tetC、tetM、tetX、tetG 和 tetW）和 1 类整合子（int-1）的丰度，分别增加了 4.7-186.9 倍和 4.25 倍。芽孢杆菌属和分枝杆菌属是富含四环素组的ARGs可能的细菌病原体宿主。这项研究表明，较高浓度的四环素残留物可以改变微生物群落并增加 ARGs 在最终污泥蚯蚓堆中的传播风险。

       Vermicomposting is a green technology used in the recycling of sewage sludge using the joint action of earthworms and microorganisms. Although tetracycline is present in abundance in sewage sludge, little attention has been given to its influence on vermicomposts. This study investigated the effects of different tetracycline concentrations (0, 100, 500 and 1000 mg/kg) on the decomposition of organic matter, microbial community and antibiotic resistance genes (ARGs) during vermicomposting of spiked sludge. The results showed that 100 mg/kg tetracycline could stimulate earthworms’ growth, accompanied by the highest humification and decomposition rates of organic matter in the sludge. The abundance of active microbial cells and diversity decreased with the increase in tetracycline concentrations. The member of Bacteroidetes dominated in the tetracycline spiked treatments, especially in the higher concentration treatments. Compared to its counterparts, the addition of tetracycline significantly increased the abundances of ARGs (tetC, tetM, tetX, tetG and tetW) and Class 1 integron (int-1) by 4.7–186.9 folds and 4.25 folds, respectively. The genera of Bacillus and Mycobacterium were the possible bacterial pathogen hosts of ARGs enriched in tetracycline added group. This study suggests that higher concentration of tetracycline residual can modify microbial communities and increase the dissemination risk of ARGs for final sludge vermicompost.

https://www.sciencedirect.com/science/article/abs/pii/S0269749119301071