摘要

       堆肥是将有机废物转化为肥料的有效方法。然而，废料通常含有大量抗生素抗性基因 (ARG) 和移动遗传元件 (MGE)，当它们传播给人类时，它们会降低抗生素治疗的功效。由于常规堆肥通常无法去除这些化合物，因此我们评估了高温超高温堆肥在去除 ARG 和 MGE 方面是否更有效，并探索了两种堆肥方法去除 ARG 的潜在机制。我们发现超高温堆肥比传统堆肥更有效地去除 ARG 和 MGE（分别为 89% 和 49%）。此外，与传统堆肥相比，ARG 和 MGE 的半衰期在超高温堆肥中较低（分别为 67% 和 58%）。更有效地去除 ARGs 和 MGEs 与潜在 ARG 宿主的细菌丰度和多样性的更高降低有关。偏最小二乘路径模型表明，MGEs 的减少在超高温堆肥中 ARG 去除中起关键作用，而 ARG 减少主要是由常规堆肥下细菌群落组成的变化驱动的。这些结果共同表明，超高温堆肥可以显着提高 ARG 和 MGE 的去除率，并且 ARG 和 MGE 的去除机制可能取决于堆肥温度。

       Composting is an efficient way to convert organic waste into fertilizers. However, waste materials often contain large amounts of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) that can reduce the efficacy of antibiotic treatments when transmitted to humans. Because conventional composting often fails to remove these compounds, we evaluated if hyperthermophilic composting with elevated temperature is more efficient at removing ARGs and MGEs and explored the underlying mechanisms of ARG removal of the two composting methods. We found that hyperthermophilic composting removed ARGs and MGEs more efficiently than conventional composting (89% and 49%, respectively). Furthermore, the half-lives of ARGs and MGEs were lower in hyperthermophilic compositing compared to conventional composting (67% and 58%, respectively). More-efficient removal of ARGs and MGEs was associated with a higher reduction in bacterial abundance and diversity of potential ARG hosts. Partial least-squares path modeling suggested that reduction of MGEs played a key role in ARG removal in hyperthermophilic composting, while ARG reduction was mainly driven by changes in bacterial community composition under conventional composting. Together these results suggest that hyperthermophilic composting can significantly enhance the removal of ARGs and MGEs and that the mechanisms of ARG and MGE removal can depend on composting temperature.

https://pubs.acs.org/doi/abs/10.1021/acs.est.7b04483