摘要

       牲畜粪便是抗生素抗性基因 (ARG) 的储存库，好氧堆肥被广泛用于回收动物粪便。本研究调查了在猪粪堆肥过程中添加 0、100 和 1000 mg/kg 的纳米零价铁 (nZVI) 对 ARG 和移动遗传元件 (MGE) 命运的影响。在100 mg/kg的nZVI下，堆肥后sul1、sul2、dfrA7、ermF和ermX的相对丰度下降了33.26%～99.31%，intI2和Tn916/1545的相对丰度分别下降了95.595%和97%。 .大多数 ARG 和 MGE 共同发生，并且它们之间具有很强的相关性。不同堆肥时期细菌群落结构明显分离，同一时期不同处理下细菌群落聚集在一起。网络分析表明，Solibacillus、Clostridium_sensu_stricto_1、Terrisporobacter、Romboutsia、Turicibacter、Lactobacillus、Planococcus、Dietzia 和 Corynebacterium_1 是 ARGs 和 MGEs 的常见潜在宿主。冗余分析表明MGEs对ARGs相对丰度的变化有关键影响。添加 100 mg/kg nZVI 可以通过降低 MGEs 的丰度来降低 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/abs/pii/S0269749119336474