摘要
      由于地下水生态系统与地表相连，水生环境中的抗生素和抗生素抗性基因（ARGs）会逐渐渗透到深层环境中，对地下水生态系统构成潜在威胁。然而，关于抗生素和ARGs在地下水生态系统中的环境风险及其生态过程的知识仍有待探索。在本研究中，通过16S rRNA基因测序和宏基因组学分析，在高四环素胁迫下进行了实验室规模的油藏，以评估微生物群落、ARGs和潜在功能的动态。尽管抗生素的存在在短期内显著降低了微生物的丰度和多样性，但在长期培养后仍保持稳定甚至增加。抗生素应激导致ARGs的多样性和丰度增加，并且有更多数量的ARGs相关物种有能力通过水平基因转移将ARGs转移到其他微生物。因此，在节点和网络水平上观察到微生物群落的更频繁关联，以及与“厌氧正构烷烃降解”和“甲基营养产甲烷”相关的抗生素抗性细菌富集的选择性压力。需要强调的是，高抗生素应激也可以阻止一些与“硫酸盐还原”、“Fe（II）氧化”、“硝酸盐还原”以及“二甲苯和甲苯降解”有关的微生物。这项研究深入了解了四环素暴露下油藏中微生物群落和功能的长期应激反应，这可能有助于阐明抗生素应激对微生物参与地下水生态系统的生物地球化学循环的影响。
Abstract
As the groundwater ecosystem is connected with surface, antibiotics and antibiotic resistance genes (ARGs) in aquatic environments will gradually infiltrate into the deep environment, posing a potential threat to groundwater ecosystem. However, knowledge on the environmental risk of antibiotics and ARGs in groundwater ecosystem and their ecological process still remains unexplored. In this study, lab-scale oil reservoirs under high tetracycline stress were performed to evaluate the dynamics of microbial communities, ARGs and potential functions by using 16S rRNA gene sequencing and metagenomics analysis. Although the presence of antibiotics remarkably reduced the microbial abundance and diversity in a short term, but remain stable or even increased after a long-term incubation. Antibiotic stress caused a greater diversity and abundance of ARGs, and higher numbers of ARGs-related species with the capacity to transfer ARGs to other microbes through horizontal gene transfer. Thus, a much more frequent associations of microbial community at both node- and network-level and a selective pressure on enrichment of antibiotic resistant bacteria related to “anaerobic n-alkane degradation” and “methylotrophic methanogenesis” were observed. It is important to emphasize that high antibiotic stress could also prevent some microbes related to “Sulfate reduction”, “Fe(II) oxidation”, “Nitrate reduction”, and “Xylene and Toluene degradation”. This study provides an insight into the long-term stress-responses of microbial communities and functions in oil reservoir under tetracycline exposure, which may help to elucidate the effect of antibiotic stress on biogeochemical cycling with microbial involvement in groundwater ecosystem.

https://www.sciencedirect.com/science/article/abs/pii/S026974912201569X