School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou, 310012, China.
School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou, 310012, China.
Chemosphere. 2023 May;324:138356. doi: 10.1016/j.chemosphere.2023.138356. Epub 2023 Mar 8.
Decreasing bioaccessible antibiotics, heavy metals, and antibiotic resistance genes (ARGs) in soil by adsorption is an attractive, but unrealized, approach for ARG risk reduction. This approach has the potential to reduce the (co)selection pressure from antibiotics and heavy metals on bacteria and ARG horizontal gene transformation to pathogens. Here, a wet-state silicon-rich biochar/ferrihydrite composite (SiC-Fe(W)) synthesized by loading ferrihydrite onto rice straw-derived biochar was examined for i) adsorption of oxytetracycline and Cu to reduce (co)selection pressure and ii) adsorption of extracellular antibiotic resistance plasmid pBR322 (containing tetA and bla) to inhibit ARG transformation. SiC-Fe(W) gained the adsorption priority of biochar (for Cu) and wet-state ferrihydrite (for oxytetracycline and pBR322) and showed adsorptive enhancement (for Cu and oxytetracycline) from a more wrinkled and exposed surface from biochar silica-dispersed ferrihydrite and a more negatively charged biochar, and the adsorption capacity for SiC-Fe(W) was 17-135 times that of soil. Correspondingly, 10 g/kg SiC-Fe(W) amendment increased the soil adsorption coefficient K by 31%-1417% and reduced the selection pressure from dissolved oxytetracycline, co-selection pressure from dissolved Cu, and transformation frequency of pBR322 (assessed with Escherichia coli). The development of Fe-O-Si bonds on silicon-rich biochar in alkaline enhanced ferrihydrite stability and adsorption capacity (for oxytetracycline), presenting a new potential strategy of biochar/ferrihydrite composite synthesis for adsorptive inhibition of ARG proliferation and transformation in ARG pollution control.
通过吸附减少土壤中生物可利用的抗生素、重金属和抗生素抗性基因（ARGs）是一种有吸引力但尚未实现的降低 ARG 风险的方法。这种方法有可能降低抗生素和重金属对细菌和 ARG 水平基因转移到病原体的（共）选择压力。在这里，研究了一种通过将水铁矿负载到水稻秸秆衍生的生物炭上合成的湿态富硅生物炭/水铁矿复合材料（SiC-Fe(W)），用于 i）吸附土霉素和 Cu 以降低（共）选择压力，以及 ii）吸附细胞外抗生素抗性质粒 pBR322（含有 tetA 和 bla）以抑制 ARG 转化。SiC-Fe(W)获得了生物炭（用于 Cu）和湿态水铁矿（用于土霉素和 pBR322）的吸附优先权，并表现出从生物炭分散的水铁矿和带更多负电荷的生物炭中获得的更褶皱和暴露的表面的吸附增强（用于 Cu 和土霉素），并且 SiC-Fe(W)的吸附容量是土壤的 17-135 倍。相应地，10 g/kg SiC-Fe(W) 添加剂使土壤吸附系数 K 增加了 31%-1417%，降低了溶解土霉素的选择压力、溶解 Cu 的共选择压力以及 pBR322 的转化频率（用大肠杆菌评估）。碱性增强了富硅生物炭上的 Fe-O-Si 键的稳定性和吸附能力（用于土霉素），为生物炭/水铁矿复合材料的合成提供了一种新的潜在策略，用于吸附抑制 ARG 污染控制中 ARG 的增殖和转化。
