摘要
      尽管有氧堆肥工艺被认为是处理畜禽粪便的一种有效方法，但细胞外抗生素抗性基因（eARGs）和细胞内抗生素耐药性基因（iARGs）的进化模式及其在堆肥过程中的水平转移尚不清楚。本文系统分析了猪粪堆肥过程中iARGs和eARGs的变化。我们发现ARGs的丰度从嗜热期反弹到成熟期。这是由于细胞增殖过程中持续性eARGs的释放和某些iARGs的增加。ARGs在堆肥群落中的结合转移频率为（1.68±0.2）×10-1堆肥产品中的转移偶联物/供体+受体（TC/D+R），与堆肥前的频率相当。然后对臭氧进行优化，以抑制ARGs的反弹和扩散。我们发现，在冷却阶段0.4 g/kg FW的低臭氧剂量不仅可以通过消除潜在宿主来显著去除iARGs（比对照少2.02个logs，12个靶向iARGs中有8个未检测到），而且通过消除微生物和微生物本身的HGT（结合和转化）效率，降低了堆肥产品之间结合和转化的可能性。总之，本研究提出了最佳臭氧氧化策略，以减轻ARGs在堆肥产品中的传播。
Abstract
Although aerobic composting process has been proposed as an efficient approach to treat livestock manure, the evolution patterns of extracellular antibiotic resistance genes (eARGs) and intracellular antibiotic resistance genes (iARGs) and their horizontal transfer during composting are unclear. Here, the variations of iARGs and eARGs during swine manure composting were systematically analyzed. We found that the abundance of ARGs rebounded from thermophilic phase to mature phase. This was due to the release of persistent eARGs and the increase of certain iARGs during cell proliferation. The conjugative transfer frequencies of ARGs in composting communities were (1.68 ± 0.2) × 10-1 Transconjugant/Donor + Recipient (TC/D + R) in composting products, which was comparable to the frequency before the composting. Ozone was then optimized to suppress the rebound and spread of ARGs. We found that the low ozone dosage of 0.4 g/kg FW in the cooling phase could not only significantly remove iARGs (2.02-logs less than the control, 8 of 12 targeted iARGs were not detected) by eliminating the potential hosts, but also decrease the possibilities of both conjugation and transformation among the composting products by eliminating both HGT (conjugation and transformation) efficiencies of microbes and microbes themselves. Collectively, this study proposes the optimal ozonation strategy to mitigate the dissemination of ARGs in the composting products.

https://www.sciencedirect.com/science/article/abs/pii/S138589472300949X