Wu Xinxin, Tang Zhurui, Li Yuqian, Du Zhe, Li Wei, Wang Simiao, Huang Caihong
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; State Environmental Protection Key Laboratory of Ecological Effect and Risk Assessment of Chemicals, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
College of Agronomy and Biotechnology, Southwest University, Chongqing, 400715, China; Chongqing Key Laboratory of Biology and Genetic Breeding for Tuber and Root Crops, Chongqing, 400715, China.
J Environ Manage. 2025 Sep;392:126781. doi: 10.1016/j.jenvman.2025.126781. Epub 2025 Jul 30.
Antibiotic resistance genes (ARGs), as emerging pollutants, jeopardize ecological and public health. Extracellular ARGs (eARGs) pose heightened risks due to their mobility, accelerating resistance spread. However, studying eARGs remains challenging given extracellular DNA's environmental instability. While aerobic composting of sewage sludge reduces ARGs, resurgence of certain genes (e.g., sulfonamide resistance) in later stages may exacerbate resistance risks. This study investigated the effects of sludge-derived biochar and commercial biochar on the reduction of intracellular and extracellular sulfonamide ARGs during sludge composting. After the addition of both biochars, intracellular ARGs (iARGs) gradually decreased as composting progressed, while eARGs initially increased before subsequently declining. The biochars reshaped the microbial community in sludge composting, significantly increasing the number of differentially enriched microbial species, altering community assembly processes, and reducing bacterial diversity and richness-key factors in ARGs reduction. The addition of both biochars also decreased the abundance of intl1, and combined with the inactivation of certain microorganisms and disruption of cell membranes, effectively suppressed the horizontal gene transfer (HGT) of eARGs. However, compared to commercial biochar, the application of sludge-derived biochar led to an increase in potential host microorganisms for ARGs, highlighting a potential risk associated with the production of biochar from sludge. Additionally, the biochars modified environmental factors such as moisture and organic content, further enhancing eARG removal. This study proposes a "waste-to-waste" circular economy model. By reusing sludge-derived biochar in composting, it not only suppresses the spread of ARGs but also achieves high-value utilization of sludge, enabling synergistic pollution control.
抗生素抗性基因（ARGs）作为新兴污染物，危害生态和公众健康。细胞外ARGs（eARGs）因其流动性而带来更高风险，加速了抗性传播。然而，鉴于细胞外DNA在环境中的不稳定性，研究eARGs仍具有挑战性。虽然污水污泥的好氧堆肥可减少ARGs，但后期某些基因（如磺胺抗性基因）的重现可能会加剧抗性风险。本研究调查了污泥衍生生物炭和商业生物炭对污泥堆肥过程中细胞内和细胞外磺胺类ARGs减少的影响。添加两种生物炭后，随着堆肥进程的推进，细胞内ARGs（iARGs）逐渐减少，而eARGs最初增加，随后下降。生物炭重塑了污泥堆肥中的微生物群落，显著增加了差异富集微生物物种的数量，改变了群落组装过程，并降低了细菌多样性和丰富度，这些都是减少ARGs的关键因素。添加两种生物炭还降低了intl1的丰度，并与某些微生物的失活和细胞膜的破坏相结合，有效抑制了eARGs的水平基因转移（HGT）。然而，与商业生物炭相比，污泥衍生生物炭的应用导致ARGs潜在宿主微生物增加，凸显了利用污泥生产生物炭的潜在风险。此外，生物炭改变了湿度和有机含量等环境因素，进一步增强了eARG的去除效果。本研究提出了一种“废物到废物”的循环经济模式。通过在堆肥中重复利用污泥衍生生物炭，不仅抑制了ARGs的传播，还实现了污泥的高价值利用，实现了协同污染控制。
