摘要

堆肥是将有机废物转化为肥料的有效方式。然而，有机废物通常含有大量抗生素抗性基因（ARG）和可移动遗传因子（MGE），这些基因可能会提高人类对抗生素的耐药性。传统堆肥往往不能去除这些化合物，所以我们研究超高温堆肥与高温能否更有效地去除ARGs和MGEs，并探讨了两种堆肥方法去除ARG的原理。我们发现超嗜热堆肥比常规堆肥更高效地去除ARG和MGE（分别为89％和49％）。此外，与传统堆肥相比，ARG和MGE在超高温合成中的半衰期较低（分别为67％和58％）。 ARGs和MGE的高效去除与细菌丰度的降低和潜在的ARG宿主的多样性有关。偏最小二乘路径建模表明，在超高温堆肥中，MGEs的减少对ARG的去除中起着关键作用，而ARG的减少主要是由传统堆肥过程中细菌群落组成的变化所驱动。总之，这些结果表明超高温堆肥可以显着提高ARG和MGE的去除，ARG和MGE去除的机制可以取决于堆肥温度。

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.

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