摘要
      畜禽粪便改良是一种常见的农业施肥方法，会加剧抗生素耐药性基因（ARG）污染，从而威胁食品安全和人类健康。另一方面，粪肥也可以作为生物炭生产，以改善土壤质量，这可能会减少粪肥中的ARGs。然而，目前尚不清楚将粪肥转化为生物炭用于土壤改良是如何以及为什么会减少ARG污染的。因此，本研究调查了猪粪（2%和5%）及其生物炭（2%和5%）改良土壤中ARG和微生物群落的变化，然后探讨了将猪粪改为生物炭如何减少ARG污染。培养28天后，未改良土壤、粪肥改良土壤和生物炭改良土壤中的ARG数分别为47、112–136和43–52。无改良土壤、粪肥改良土壤和生物炭改良土壤中ARG的丰度分别为7.66×107、4.32×109-1.42×1011和8.44×107–9.67×107拷贝g−1干土。与粪肥改良土壤相比，其生物炭改良剂使土壤中的ARG丰度降低了2-4个数量级，ARG数量减少了70-93。此外，粪肥改良剂发生了改变，而生物炭并没有改变细菌的多样性和组成。土壤性质和可移动遗传元素（MGE）的变化可以解释ARGs的变化。相对于粪肥改良剂，其生物炭改良剂降低了土壤中的移动遗传元素（MGE）、变形杆菌和拟杆菌，这解释了ARGs丰度和多样性的降低；然而，在生物炭改良的土壤中，变形杆菌和拟杆菌中携带的多药耐药基因仍然丰富。这项研究表明，将粪肥转化为生物炭作为土壤改良剂可以帮助控制粪肥ARGs的传播。
Abstract
Livestock manure amendment, a common fertilization method for agricultural practice, can exacerbate antibiotic resistance gene (ARG) pollution, thus threatening food safety and human health. On the other hand, manure can also be produced as biochar to improve soil quality, which may reduce ARGs inside manure. However, it is unclear how and why shifting manure to biochar for soil amendment reduces ARG pollution. Thus, this study investigated the variations of ARGs and microbial communities in soil amended with swine manure (2 % and 5 %) and its biochar (2 % and 5 %) and then explored how shifting swine manure to biochar reduced ARG contamination. After 28 d incubation, ARG number in soil without amendment, manure-amended soils, and biochar-amended soils were 47, 112–136, and 43–52, respectively. ARG abundance in soil without amendment, manure-amended soils, and biochar-amended soils were 7.66 × 107, 4.32 × 109 - 1.42 × 1011, and 8.44 × 107–9.67 × 107 copies g−1 dry soil, respectively. Compared to manure-amended soils, its biochar amendments reduced ARG abundance by 2–4 orders of magnitude and ARG number by 70–93 in soil. Besides, manure amendment altered while biochar did not alter bacterial diversity and composition. The changed soil properties and mobile genetic elements (MGEs) could explain the changes in ARGs. Relative to manure amendments, its biochar amendments reduced mobile genetic elements (MGEs), Proteobacteria and Bacteroidetes in soil, which explained the reduced abundance and diversity of ARGs; however, the multidrug-resistance genes harbored in Proteobacteria and Bacteroidetes were still abundant in biochar-amended soil. This study suggests that converting manure to biochar as a soil amendment can help control the spread of manure ARGs.

https://www.sciencedirect.com/science/article/abs/pii/S0048969723006629