摘要
      在本研究中，通过直接（细菌群落、移动遗传元件和群体感应）和间接（环境因素和抗生素）两种方式分析了牛粪堆肥中的赤泥（RM）对抗生素抗性基因（ARGs）命运的影响。结果表明，RM降低了10个ARG和4个可移动遗传元件（MGE）的总相对丰度。与第0天相比，第47天T（添加RM）中总ARGs和MGE的相对丰度分别下降了53.48%和22.30%。同时，RM的修饰显著增加了群体猝灭（QQ）中lsrK、pvdQ和ahlD的丰度，降低了群体感应（QS）中luxS的丰度（P<0.05），从而减弱了细胞间基因的交流频率。微生物群落和网络分析表明，ARGs的25个潜在宿主主要与厚壁菌门、变形菌门和放线菌门有关。冗余分析（RDA）和结构方程模型（SEM）进一步表明，RM通过调节抗生素含量和环境因素（温度、pH、水分含量和有机物含量）来改变微生物群落结构，从而影响QS和MGEs介导的ARGs中的水平基因转移（HGT）。这些结果为堆肥过程中ARGs的传播机制和去除提供了新的见解。
Abstract
In this study, the amendment of red mud (RM) in dairy manure composting on the fate of antibiotic resistance genes (ARGs) by both direct (bacteria community, mobile genetic elements and quorum sensing) and indirect ways (environmental factors and antibiotics) was analyzed. The results showed that RM reduced the total relative abundances of 10 ARGs and 4 mobile genetic elements (MGEs). And the relative abundances of total ARGs and MGEs decreased by 53.48% and 22.30% in T (with RM added) on day 47 compared with day 0. Meanwhile, the modification of RM significantly increased the abundance of lsrK, pvdQ and ahlD in quorum quenching (QQ) and decreased the abundance of luxS in quorum sensing (QS) (P < 0.05), thereby attenuating the intercellular genes frequency of communication. The microbial community and network analysis showed that 25 potential hosts of ARGs were mainly related to Firmicutes, Proteobacteria and Actinobacteria. Redundancy analysis (RDA) and structural equation model (SEM) further indicated that RM altered microbial community structure by regulating antibiotic content and environmental factors (temperature, pH, moisture content and organic matter content), which then affected horizontal gene transfer (HGT) in ARGs mediated by QS and MGEs. These results provide new insights into the dissemination mechanism and removal of ARGs in composting process.

https://www.sciencedirect.com/science/article/abs/pii/S0269749122020103