【摘要】 本研究选取热解温度为300～600℃的芦苇（Phragmites australis）和芦竹（Arundo donax）生物炭释放的DBC,探究其对抗性质粒pBR322向大肠杆菌（Escherichia coli）DH5α转化的影响。结果表明，DBC对pBR322质粒的转化具有低浓度(1 mg·L^-1)促进、高浓度(10 mg·L^-1)抑制的规律，且抑制效果随热解温度的上升而增强。DBC能够破坏pBR322质粒的结构，导致eARGs失活。低浓度DBC中的溶解性微生物代谢产物类物质和重金属等物质可诱导受体细菌SOS应答，从而促进其对质粒的摄取。中高浓度(5～10 mg·L^-1)的DBC能够激活受体菌的应激防御系统，降低细胞膜透性，阻碍了质粒进入感受态。此外，随机森林模型（R²=0.627 9,均方误差为0.002 67）证实DBC中富里酸类、溶解性微生物代谢产物类物质、pH和重金属在转化过程中起着关键作用。结构方程模型证明DNA复制活性的降低是抑制eARGs转化的主控因子。本研究拓展了水环境中溶解性有机质驱动新污染物ARGs环境归趋的理解，为水环境中基于生物炭的ARGs污染阻控技术的建立提供了科学依据。更多还原

【Abstract】 The coexistence of extracellular antibiotic resistance genes（eARGs） and dissolved biochar（DBC） in surface water environments has drawn widespread attention. However, the effect of DBC on the transformation-mediated horizontal transferprocess of eARGs in aquatic environment remains unknown. In this study, DBC released from reed（Phragmites australis） and reed bamboo（Arundo donax） biochar at different pyrolysis temperatures（300～600 ℃） was selected to investigate its effect on the transformation of the resistance plasmid pBR322 into Escherichia coli（E. coli） DH5α. The results showed that the effect of DBC on the transformation of pBR322 was promoted by low concentration(1 mg·L^-1) and inhibited by high concentration(10 mg·L^-1), and the inhibitory effect of DBC increased with the rising of pyrolysis temperature. DBC could inactivate the eARGs through disrupting the structure of the pBR322 plasmid. At low concentrations, soluble microbial byproduct-like material, and heavy metals in DBC can induce its SOS responsein recipient bacteria, thereby facilitating their uptake of plasmids. However, at high concentrations(5～10 mg·L^-1), DBC activated the cellular stress defense system of the bacteria, decreased cell membrane permeability, and hindered the access of plasmid to the competent cell. Meanwhile, random forest model（R²= 0.627 9, MSE=0.002 67） revealed that fulvic acid, soluble microbial byproduct-like material, pH value and heavy metals in DBC play key roles in the transformation process. In addition, structural equation modelling demonstrated that the reduction of DNA replication activity is the main factor inhibiting the transformation of eARGs.This study extends our understanding of how dissolved organic matter drives the environmental fate of emerging pollutants ARGs in aquatic environments, providing a scientific basis for the establishment of biochar-based pollution control technologies for ARGs in aquatic environments.更多还原