Antibiotic resistance genes (ARGs) in soil pose a major challenge to global environment and health. The development of effective technologies to reduce their negative effects has implications for maintaining soil health and human health. Biochar would be a suitable control material due to its characteristics of high carbon content, large surface area, excellent adsorption capacity, and economic advantages. There are three mechanisms underlying its negative effects on the abundance of ARGs: 1) adsorption of certain pollutants (e.g., antibiotics and heavy metals) to reduce the co-selective pressure of ARGs; 2) alteration of microbial composition through altering soil physico-chemical properties, and thereby limiting the ability of bacteria to undergo horizontal transfer of ARGs; 3) direct impairment of horizontal gene transfer by the adsorption of horizontal transfer vectors such as plasmids, transposons, and integrons. However, the negative effect of biochar depends on the source of material, pyrolysis process, and its amount added. Furthermore, field aging of biochar may reduce its ability to block ARGs. Endogenous contaminants of biochar, such as polycyclic aromatic hydrocarbons and heavy metals, may cause the enrichment of specific antibiotic-resistant bacteria in the environment or induce horizontal gene transfer. In further studies, suitable biochar should be selected according to soil environments, and biochar aging control measures should be taken to improve its retarding effect on ARGs.
土壤中抗生素抗性基因(ARGs)污染是全世界面临的重大环境和健康挑战,开发有效技术以减少其负面影响对维护土壤和人类健康至关重要。生物炭具有高碳含量、大表面积、良好的吸附性能和经济优势,可能是一种非常合适的阻控材料。其对ARGs的阻控作用可能归因于以下3种机制: 1) 吸附某些污染物,如抗生素和重金属,减弱ARGs的共选择性压力;2) 通过改变土壤理化特性影响微生物种群结构,从而限制细菌之间ARGs的水平转移;3) 通过吸附或破坏质粒、转座子、整合子等水平转移载体,直接减弱基因水平转移能力。但生物炭对ARGs的阻控效果取决于生物炭的物料来源、热解工艺和添加水平等。此外,生物炭的老化可能会降低其阻控ARGs的效果。生物炭的内源性污染物,如多环芳烃和重金属,也可能导致环境中特定抗生素抗性细菌的富集或诱导水平基因转移。在后续研究中,应根据土壤环境选择合适的生物炭种类,并采取生物炭老化控制措施,以进一步提高生物炭对ARGs的阻控作用。.
Keywords: antibiotic resistance genes; biochar; soil rehabilitation.