摘要

       畜禽粪便抗性基因导致的环境污染已成为亟待解决的严重问题。然而，很少有研究关注在同时处理家畜粪便和尿液中去除抗性基因。本研究调查了猪粪在异位发酵系统 (EFS) 中高温发酵过程中抗生素抗性基因 (ARGs)、金属抗性基因 (MRGs) 和 1 类整合子整合酶基因 (intI1) 的命运，这被认为是一种有效处理粪便和尿液的新系统。 EFS 中 MRGs 和四环素抗性基因的丰度低 34.44-97.71%。重金属的补充显着增加了intI1的丰度，其中铜的增强作用比锌的增强作用更为突出。在高铜水平（A2）观察到最高丰度的抗性基因和 intI1，表明 Cu 可以通过整合子增加抗性基因的传播。网络分析揭示了 ARGs、MRGs 和 intI1 的共同出现，并且这些基因可能共享相同的宿主细菌。冗余分析表明，细菌群落解释了 ARGs 的大部分变化，环境因素通过调节细菌群落组成对 ARGs 丰度产生影响。鞘氨醇单胞菌、毛单胞菌、不动杆菌、乳杆菌、巴尔通体、根瘤菌和拟杆菌减少是耐药基因减少的主要原因。这些结果表明，EFS 可以减少同时处理家畜粪便和尿液的抗性基因。

       Environmental pollution due to resistance genes from livestock manure has become a serious issue that needs to be resolved. However, little studies focused on the removal of resistance genes in simultaneous processing of livestock feces and urine. This study investigated the fate of antibiotic resistance genes (ARGs), metal resistance genes (MRGs), and class 1 integron-integrase gene (intI1) during thermophilic fermentation of swine manure in an ectopic fermentation system (EFS), which has been regarded as a novel system for efficiently treating both feces and urine. The abundances of MRGs and tetracycline resistance genes were 34.44–97.71% lower in the EFS. The supplementation of heavy metals significantly increased the abundance of intI1, with the enhancement effect of copper being more prominent than that of zinc. The highest abundances of resistance genes and intI1 were observed at high Cu levels (A2), indicating that Cu can increase the spreading of resistance genes through integrons. Network analysis revealed the co-occurrence of ARGs, MRGs, and intI1, and these genes potentially shared the same host bacteria. Redundancy analysis showed that the bacterial community explained most of the variations in ARGs, and environmental factors had influences on ARGs abundances by modulating the bacterial community composition. The decreased Sphingomonas, Comamonas, Acinetobacter, Lactobacillus, Bartonella, Rhizobium, and Bacteroides were mainly responsible for the reduced resistance genes. These results demonstrate that EFS can reduce resistance genes in simultaneous processing of livestock feces and urine.

https://www.sciencedirect.com/science/article/pii/S0147651321000920