Hebei Key Laboratory of Heavy Metal Deep-Remediation in Water and Resource Reuse, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao 066004, China; Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture, China-New Zealand Joint Laboratory for Soil Molecular Ecology, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Hebei Key Laboratory of Heavy Metal Deep-Remediation in Water and Resource Reuse, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao 066004, China.
Sci Total Environ. 2023 Apr 20;870:161785. doi: 10.1016/j.scitotenv.2023.161785. Epub 2023 Jan 31.
Using high-throughput quantitative PCR and next generation sequencing, the impact of land application of raw and composted gentamicin fermentation waste (GFW) on antibiotic resistance genes (ARGs) in maize seeds was studied in a three-year field trial. The raw and composted GFW changed both the bacterial community composition and the ARGs diversity in the maize seeds compared to non-amended controls and chemical fertilizer. The abundance of ARGs after raw GFW amendment was significantly higher than other treatments because of a high abundance of aadA1, qacEdeltal and aph(2')-Id-02; probably induced by gentamicin selection pressure in maize tissues. Meanwhile, the potential host of these three ARGs, pathogenic bacteria Tenacibaculum, also increased significantly in maize seeds after the application of raw GFW. But our result proved that composting could weaken the risk posed by GFW. We further reveal that the key biotic driver for shaping the ARG profiles in maize seeds is bacterial community followed by heavy metal resistance genes, and ARGs are more likely located on bacterial chromosomes. Our findings provide new insight into ARGs dispersal mechanism in maize seeds after long-term GFW application, demonstrate the potential benefits of composting the GFW to reduce risks as well as the potential efficient management method to GFW.
采用高通量定量 PCR 和下一代测序技术，在为期三年的田间试验中研究了未经处理和堆肥的庆大霉素发酵废物（GFW）施用于玉米种子对抗生素抗性基因（ARGs）的影响。与未施肥对照和化学肥料相比，未经处理和堆肥的 GFW 改变了玉米种子中的细菌群落组成和 ARGs 多样性。由于在玉米组织中受到庆大霉素的选择压力，原始 GFW 处理后 ARGs 的丰度明显高于其他处理，aadA1、qacEdeltal 和 aph(2')-Id-02 的丰度较高。同时，在施用原始 GFW 后，这些三个 ARGs 的潜在宿主——病原菌 Tenacibaculum 在玉米种子中也显著增加。但我们的结果证明堆肥可以降低 GFW 带来的风险。我们进一步揭示了塑造玉米种子中 ARG 图谱的关键生物驱动因素是细菌群落，其次是重金属抗性基因，并且 ARGs 更有可能位于细菌染色体上。我们的研究结果为长期 GFW 施用后玉米种子中 ARGs 传播机制提供了新的见解，证明了堆肥 GFW 以降低风险的潜在益处，以及 GFW 的潜在有效管理方法。
