Jia Wei-Li, Wang Ben, Qiao Lu-Kai, Gao Fang-Zhou, Liu Wang-Rong, He Liang-Ying, Ying Guang-Guo
SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China.
Guangdong Engineering & Technology Research Center for System Control of Livestock and Poultry Breeding Pollution, South China Institute of Environmental Sciences, Ministry of Ecology and Environment of the PR China, Guangzhou 510655, China.
J Hazard Mater. 2025 Aug 15;494:138593. doi: 10.1016/j.jhazmat.2025.138593. Epub 2025 May 12.
Aerobic composting is an effective method for reducing the abundance of antibiotic resistance genes (ARGs), but its effectiveness is influenced by the complex conditions during the process. However, the impact of composting conditions on the fate of ARGs and the underlying mechanisms remains unclear. This study examined the profile of ARGs, their mobility potential, hosts, and the risk of antibiotic resistome under different chicken manure composting conditions. A total of 708 ARGs were identified, and composting reduced their relative abundance by 29.4 %-82.4 %. Composting amendments and aeration rates exhibited similar elimination efficiencies for ARGs at different levels. However, low initial moisture content (50 %) caused a rebound in ARG abundance during the maturation phase. ARGs were mainly located on plasmids. After composting, the percentage of plasmid-born ARGs decreased from 46.3 %-70.8 % to 28.4 %-49.0 %. ARGs co-localized with mobile genetic elements displayed similar trends. The tolerance of Firmicutes to low moisture content played a key role in the rebound of ARGs and variations in their mobility potential. Composting reduced antibiotic resistance and ARG mobility in pathogens. Conversely, low moisture content hindered this attenuation effect in Firmicutes, which increased antibiotic resistome risk. This study provides comprehensive insights into the fate of ARGs and highlights the environmental risks of ARGs during composting.
好氧堆肥是一种降低抗生素抗性基因（ARGs）丰度的有效方法，但其有效性受堆肥过程中复杂条件的影响。然而，堆肥条件对ARGs归宿及其潜在机制的影响仍不清楚。本研究考察了不同鸡粪堆肥条件下ARGs的分布特征、移动潜力、宿主以及抗生素抗性组的风险。共鉴定出708种ARGs，堆肥使其相对丰度降低了29.4%-82.4%。堆肥添加剂和通气速率对不同水平的ARGs表现出相似的去除效率。然而，低初始水分含量（50%）导致成熟期ARG丰度反弹。ARGs主要位于质粒上。堆肥后，质粒携带的ARGs百分比从46.3%-70.8%降至28.4%-49.0%。与可移动遗传元件共定位的ARGs呈现相似趋势。厚壁菌门对低水分含量的耐受性在ARGs反弹及其移动潜力变化中起关键作用。堆肥降低了病原体中的抗生素抗性和ARGs移动性。相反，低水分含量阻碍了厚壁菌门中的这种衰减效应，增加了抗生素抗性组风险。本研究全面深入地了解了ARGs的归宿，并突出了堆肥过程中ARGs的环境风险。
