摘要

     畜禽粪便是抗生素抗性基因（ARGs）的贮存库，好氧堆肥技术广泛应用于畜禽粪便的循环利用。本文研究了添加不同浓度的纳米零价铁（nZVI）0、100和1000mg/kg对猪粪堆肥过程中ARGs和可移动基因元件（MGEs）的影响。在nZVI浓度为100mg/kg时，堆肥后sul1、sul2、dfrA7、ermF和ermX的相对丰度降低了33.26-99.31%，intI2和Tn916/1545的相对丰度分别降低了95.59%和97.65%。ARGs和MGEs多数同时发生，且相互间有较强的相关性。堆肥过程中，细菌群落结构明显分离，在同一时期不同处理下，细菌群落结构聚集在一起。网络分析表明明，土壤芽芽孢杆菌，梭状芽胞杆菌，Terrisporobacter，Romboutsia，Turicibacter，乳酸菌，动球菌，迪茨氏菌，棒状杆菌是ARGs和MGEs的潜在共同宿主。冗余分析表明，MGEs对ARGs相对丰度的变化有重要影响。添加100mg/kg的nZVI可以降低MGEs的含量，从而降低ARGs的环境风险。

      Livestock manure is a reservoir for antibiotic resistance genes (ARGs), and aerobic composting is used widely for recycling animal manure. This study investigated the effects of adding nano-zerovalent iron (nZVI) at 0, 100, and 1000 mg/kg on the fates of ARGs and mobile genetic elements (MGEs) during swine manure composting. Under nZVI at 100 mg/kg, the relative abundances of sul1, sul2, dfrA7, ermF, and ermX decreased by 33.26–99.31% after composting, and the relative abundances of intI2 and Tn916/1545 decreased by 95.59% and 97.65%, respectively. Most of the ARGs and MGEs co-occurred and they had strong correlations with each other. The bacterial community structure was significantly separated by the composting periods, and they clustered together under different treatments in the same phase. Network analysis showed that Solibacillus, Clostridium_sensu_stricto_1, Terrisporobacter, Romboutsia, Turicibacter, Lactobacillus, Planococcus, Dietzia, and Corynebacterium_1 were common potential hosts of ARGs and MGEs. Redundancy analysis suggested that MGEs had key effects on the variations in the relative abundances of ARGs. Adding 100 mg/kg nZVI could reduce the environmental risk of ARGs by decreasing the abundances of MGEs.

     https://www.sciencedirect.com/science/article/pii/S0269749119336474