摘要
      抗生素抗性基因污染农业土壤的修复对保护食品安全和人类健康具有重要意义。降低土壤中铜的有效性可能会控制对ARGs的耐药性。然而，应用纳米生物炭和蜡状芽孢杆菌来减缓ARGs在铜污染土壤中传播的可行性尚不清楚。因此，本研究调查了不同颗粒尺寸的生物炭的使用（2 % 苹果枝生物炭和0.5 % 纳米生物炭）和3 克 m−2蜡状芽孢杆菌在种植生菜的60天盆栽实验中。单一施用和联合施用对Cu污染土壤中ARGs丰度的影响 = 200 毫克 kg−1）进行比较，并探讨了相关机制。研究表明，单独添加生物炭对缓解土壤-生菜系统中的ARGs是有害的。3的组合应用 克 m−2蜡状芽孢杆菌和0.5 % 纳米生物炭有效抑制了铜污染土壤中ARGs的增殖，3 克 m−2蜡状芽孢杆菌能有效抑制莴苣中ARGs的增殖。偏最小二乘路径建模和网络分析表明，细菌群落和可移动遗传元素是影响根际土壤ARGs丰度的关键因素，铜抗性基因和生物可利用铜（酸可提取态Cu（F1）） + 还原态Cu（F2））具有较少的直接影响。细菌群落是影响生菜中ARGs丰度的关键因素。红细菌（变形杆菌）、棒状杆菌（放线菌）和甲基细菌（变形菌）可能是莴苣植物中ARGs的宿主。蜡状芽孢杆菌和纳米生物炭通过改善土壤性质和降低土壤中Cu的生物利用度，以及直接或间接改变土壤和生菜中的细菌群落组成，从而阻碍ARGs向地上植物部分的运输，从而影响ARGs的丰度。
Abstract
The remediation of agricultural soil contaminated by antibiotic resistance genes (ARGs) is of great significance for protecting food safety and human health. Reducing the availability of copper in soil may control coresistance to ARGs. However, the feasibility of applying nano-biochar and Bacillus cereus to mitigate the spread of ARGs in Cu contaminated soil remains unclear. Therefore, this study investigated the use of biochar with different particle sizes (2 % apple branch biochar and 0.5 % nano-biochar) and 3 g m−2 B. cereus in a 60-day pot experiment with growing lettuce. The effects of single and combined application on the abundances of ARGs in Cu-contaminated soil (Cu = 200 mg kg−1) were compared, and the related mechanisms were explored. Studies have shown that the addition of biochar alone is detrimental to mitigating ARGs in soil–lettuce systems. The combined application of 3 g m−2 B. cereus and 0.5 % nano-biochar effectively inhibited the proliferation of ARGs in Cu-contaminated soil, and 3 g m−2 B. cereus effectively inhibited the proliferation of ARGs in lettuce. Partial least squares-path modeling and network analysis showed that bacterial communities and mobile genetic elements were the key factors that affected the abundances of ARGs in rhizosphere soil, and Cu resistance genes and bioavailable copper (acid extractable state Cu (F1) + reducing state Cu (F2)) had less direct impacts. The bacterial community was the key factor that affected the abundances of ARGs in lettuce. Rhodobacter (Proteobacteria), Corynebacterium (Actinobacteria), and Methylobacterium (Proteobacteria) may have been hosts of ARGs in lettuce plants. B. cereus and nano-biochar affected the abundances of ARGs by improving the soil properties and reducing the soil bioavailability of Cu, as well as directly or indirectly changing the bacterial community composition in soil and lettuce, thereby impeding the transport of ARGs to aboveground plant parts.

https://www.sciencedirect.com/science/article/abs/pii/S0048969723020417