摘要
      生物质改良剂在减少土壤环境中的抗生素抗性基因（ARGs）方面有许多好处。然而，关于原料生物质及其热解生物炭对ARGs的影响，仍有争议的结果，对其影响机制的探索仍处于初级阶段。在此，我们研究了椰子壳及其生物炭施用有机肥后土壤ARGs的变化。结果表明，椰子壳生物炭可以有效减少ARGs，目标ARGs减少61.54%，高于添加生椰子壳（p<0.05）。结构方程模型表明，ARGs受到环境因素变化的显著影响，主要是通过调节细菌群落。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性，具有较大的比表面积（476.66m2/g）和孔隙（孔径约1.207nm，总孔隙体积：0.2451m3/g），这显著增强了土壤的异质性，从而形成了限制抗性细菌增殖和ARGs繁殖的屏障。该结果为控制土壤施用有机肥后ARGs的发展提供了一种方法。
Abstract
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 m2/g) and pores (pore diameter approximately 1.207 nm, total pore volume: 0.2451 m3/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.

https://www.sciencedirect.com/science/article/abs/pii/S0304389422011128