Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China.
College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin 300071, China.
J Hazard Mater. 2022 Sep 5;437:129322. doi: 10.1016/j.jhazmat.2022.129322. Epub 2022 Jun 7.
Biomass amendments have numerous benefits in reducing antibiotic resistance genes (ARGs) in the soil environment. However, there are debatable outcomes regarding the effect of raw biomass and its pyrolytic biochar on ARGs, and the exploration of the influence mechanism is still in infancy. Herein, we investigated the changes in soil ARGs under the organic fertilizer application with coconut shell and its biochar. The results showed that the coconut shell biochar could effectively diminish ARGs, with 61.54% reduction in target ARGs, which was higher than that adding raw coconut shells (p < 0.05). Structural equation modeling indicated that ARGs were significantly affected by changes in environmental factors, mainly by modulating bacterial communities. Neutral community model and network analysis demonstrated that the coconut shell biochar can restrict the species dispersal, thereby mitigating the spread of ARGs. Also, coconut shell biochar exhibited strong adsorption, with a large specific surface area (476.66 m/g) and pores (pore diameter approximately 1.207 nm, total pore volume: 0.2451 m/g), which markedly enhanced soil heterogeneity that created a barrier to limit the resistant bacteria proliferation and ARGs propagation. The outcome gives an approach to control the development of ARGs after organic fertilizer application into soil.
生物量添加物在减少土壤环境中的抗生素抗性基因（ARGs）方面具有诸多益处。然而，关于原始生物量及其热解生物炭对 ARGs 的影响仍存在争议，并且对其影响机制的探索仍处于起步阶段。在此，我们研究了施用椰子壳及其生物炭有机肥时土壤中 ARGs 的变化。结果表明，椰子壳生物炭可有效减少 ARGs，目标 ARGs 的减少率达到 61.54%，高于添加原始椰子壳（p<0.05）。结构方程模型表明，ARGs 受环境因素变化的显著影响，主要通过调节细菌群落来实现。中性群落模型和网络分析表明，椰子壳生物炭可以限制物种的扩散，从而减缓 ARGs 的传播。此外，椰子壳生物炭表现出较强的吸附能力，具有较大的比表面积（476.66 m/g）和孔（孔径约为 1.207 nm，总孔体积：0.2451 m/g），显著增强了土壤异质性，为限制抗性细菌增殖和 ARGs 传播创造了障碍。该结果为控制有机肥施入土壤后 ARGs 的发展提供了一种方法。
