摘要

    畜禽粪便是进入环境的抗生素抗性基因（ARG）的主要来源。这项研究评估了猪粪堆肥过程中接种成熟堆肥（MC）对ARG命运和细菌群落的影响。结果表明，由于嗜热细菌（芽孢杆菌，嗜热菌和嗜热芽孢杆菌）的快速生长和繁殖，MC延长了嗜热期并促进了有机物的分解。堆肥后，MC显着降低了ARGs（1.02个对数）和移动遗传元件（MGEs）（1.70个对数）的相对丰度，尤其是对磺胺抗性的基因。 MC的总ARGs去除率比对照组高1.11倍。冗余分析和结构方程建模表明，由MGEs（ISCR1和intI1）介导的水平基因转移是与堆肥期间ARGs变化有关的主要直接因素，而C / N比和pH是两个最重要的间接因素。网络分析表明，包括核糖核酸菌，梭状芽孢杆菌_stricto_1和Terrisporobacter的Firmicutes成员是ARGs和MGEs的主要细菌宿主。 MC通过减少细菌宿主的丰度降低了ARGs传播的风险。因此，MC是降低ARGs增殖风险的有前途的策略。

    Livestock manure is a major source of antibiotic resistance genes (ARGs) that enter the environment. This study assessed the effects of inoculation with mature compost (MC) on the fates of ARGs and the bacterial community during swine manure composting. The results showed that MC prolonged the thermophilic period and promoted the decomposition of organic matter, which was due to the rapid growth and reproduction of thermophilic bacteria (Bacillus, Thermobifida, and Thermobacillus). MC significantly reduced the relative abundances of ARGs (1.02 logs) and mobile genetic elements (MGEs) (1.70 logs) after composting, especially sulfanilamide resistance genes. The total ARGs removal rate was 1.11 times higher in MC than the control. Redundancy analysis and structural equation modeling showed that horizontal gene transfer mediated by MGEs (ISCR1 and intI1) was the main direct factor related to the changes in ARGs during composting, whereas the C/N ratio and pH were the two most important indirect factors. Network analysis showed that members of Firmicutes comprising Romboutsia, Clostridisensu_stricto_1, and Terrisporobacter were the main bacterial hosts of ARGs and MGEs. MC reduced the risk of ARGs transmission by decreasing the abundances of bacterial hosts. Thus, MC is a promising strategy for reducing the proliferation risk of ARGs.

     https://www.sciencedirect.com/science/article/abs/pii/S0304389421000996