摘要
      通过有管理的含水层补给（MAR）储存再生水是缓解地下水超采和同时实现水资源循环利用的有效策略。然而，再生水中的β-内酰胺类抗生素会对含水层系统造成压力，重塑微生物群落，并影响抗生素抗性基因（ARGs）的出现和流行。在本研究中，采用三根砂土柱（高1.5 m，内径14 cm）模拟MAR，并连续补给含有阿莫西林（AMO）、氨苄青霉素（AMP）或苯唑西林（OXA）的合成再生水120 d。研究了β-内酰胺和氮的时空衰减，阐述了微生物协作和抗性机制。生物降解是消除β-内酰胺的主要途径，当迁移30cm时，AMO和AMP被消除，而OXA在整个柱中衰减，最终去除效率为82%。此外，难治性OXA诱导了更多的ARGs产生，比AMO和AMP柱高出约10%和13%。流出泵和抗生素灭活是两种主要的耐药机制。NO3−-N沿补给方向逐渐减少（AMO、AMP和OXA分别减少26%、38%和49%）。微生物共生网络表明，氮循环细菌是含水层群落中的关键物种，氨化为氨氧化古菌（AOA）的硝化过程提供了NH4+-N，促进了MAR过程中脱氮的进一步反硝化。氮循环细菌是ARG的关键和活性宿主，在抗生素胁迫下可以保持氮转化活性。总之，氮循环细菌在MAR期间对营养不良环境和β-内酰胺暴露表现出密切的协作和弹性抵抗。
Abstract
Storing reclaimed water via managed aquifer recharge (MAR) is an effective strategy for alleviating groundwater overdraft and achieving water resource recycling simultaneously. However, β-lactam antibiotics in the reclaimed water can induce stress on aquifer system, reshape microbial community, and affect the emergence and prevalence of antibiotic resistance genes (ARGs). In this study, three sandy soil columns (H 1.5 m, ID 14 cm) were employed to simulate MAR, and synthetic reclaimed water containing either amoxicillin (AMO), ampicillin (AMP) or oxacillin (OXA) was continuously recharged for 120 d The temporal and spatial attenuation of β-lactams and nitrogen was studied, and microbial collaboration and the resistance mechanism were elaborated. Biodegradation is the main pathway for β-lactams elimination, AMO and AMP were eliminated when migrating 30 cm, while the attenuation of OXA experienced in the whole column with final removal efficiency of 82%. Moreover, refractory OXA induced more ARGs production, and approximately 10% and 13% higher than that of AMO and AMP columns. Efflux pump and antibiotics inactivation were the two major resistance mechanisms. NO3−-N gradually decreased (by 26%, 38%, and 49% for AMO, AMP, and OXA, respectively) along the recharge direction. Microbial co-occurrence network revealed that nitrogen-cycling bacteria were the keystone species in aquifer community, and ammonation provided NH4+-N for the nitrification process of ammonia-oxidizing archaea (AOA), promoting the further denitrification for nitrogen removal in MAR process. Nitrogen-cycling bacteria were the key and active ARG hosts, which could keep nitrogen transformation activity under antibiotics stress. In sum, nitrogen-cycling bacteria exhibited intimate collaboration and elastic resistance in response to the malnutrition environment and β-lactams exposure during MAR.

https://www.sciencedirect.com/science/article/abs/pii/S0043135423000581