Ahmed Imtiaz, Zhuang Zixian, Zhang Dong, Li Peng, Zhang Bo
School of Environmental Science and Engineering Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China; State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
School of Environmental Science and Engineering Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China.
J Hazard Mater. 2025 Aug 15;494:138519. doi: 10.1016/j.jhazmat.2025.138519. Epub 2025 May 9.
The widespread use of antibiotics in animal farming has accelerated the dissemination of antibiotic resistance genes (ARGs). Aerobic composting is an effective method for managing animal manure, yet its effects on intracellular (iARGs) and extracellular ARGs (eARGs) under different temperature regimes including control (LT), gradual increase temperature (GT), and initially enriched temperature (HT) remain unclear. This study investigated the dynamics of iARGs and eARGs across these temperature gradients during composting. Initial composting substrate harbored higher levels of iARGs than eARGs. After composting, ARG rebound was primarily driven by eARG enrichment. On day 40, iARGs decreased by 3.1 logs in HT, 1.2 logs in LT, and 1 log in GT, while eARGs decreased by 0.9 log only in HT but increased in LT and GT. Initially phyla Firmicutes and Proteobacteria were dominated, the microbial community shifted to Bacteroidetes in LT, Actinobacteria in GT, and retained Firmicutes dominance in HT on day 40. Metagenomic analysis revealed that 68 % ARG reduction was associated with plasmid-borne ARGs, with reductions of 83.4 % in HT, 68.2 % in GT, and 51.6 % in LT, whereas non-plasmid ARGs were reduced by up to 75 % across all treatments. Notably, plasmid conjugation was significantly inhibited under HT and GT conditions.
抗生素在畜牧业中的广泛使用加速了抗生素抗性基因（ARGs）的传播。好氧堆肥是处理动物粪便的有效方法，但其在包括对照（LT）、温度逐渐升高（GT）和初始富集温度（HT）等不同温度条件下对细胞内ARGs（iARGs）和细胞外ARGs（eARGs）的影响仍不清楚。本研究调查了堆肥过程中这些温度梯度下iARGs和eARGs的动态变化。堆肥初始底物中iARGs的含量高于eARGs。堆肥后，ARG反弹主要由eARG富集驱动。在第40天，HT组中iARGs减少了3.1个对数，LT组减少了1.2个对数，GT组减少了1个对数，而eARGs仅在HT组减少了0.9个对数，在LT组和GT组中增加。最初厚壁菌门和变形菌门占主导，到第40天，微生物群落转变为LT组中的拟杆菌门、GT组中的放线菌门，HT组中仍以厚壁菌门为主导。宏基因组分析显示，68%的ARG减少与质粒携带的ARG有关，HT组减少83.4%，GT组减少68.2%，LT组减少51.6%，而所有处理中非质粒ARG最多减少75%。值得注意的是，在HT和GT条件下，质粒接合受到显著抑制。
