Survival strategies of Eisenia fetida in antibiotic-contaminated soil based on screening canonical correlation analysis model

Soil pollution from antibiotics has become increasingly severe, posing significant environmental and human health threats. Many soil organisms can survive and sustain their roles in maintaining soil ecosystems, even in polluted conditions. Exploring the life-sustaining mechanisms of these organisms in contaminated environments is scientifically significant. This study used Eisenia fetida as the test organism and antibiotics (oxytetracycline hydrochloride) as exogenous stress substances. Oxidative stress response experiments were conducted using the artificial soil method to examine the response of earthworms to oxidative stress. Additionally, 16S rRNA technology was employed to analyze the succession of microbial community structures inside and outside the earthworms. A screening canonical correlation analysis (SCCA) model was developed to investigate the relationship between microbial communities and earthworm oxidative stress system under oxytetracycline stress, revealing survival strategies in antibiotic-contaminated soil. The results showed that Proteobacteria and Bacteriodetes were the dominant phyla of microbial communities in earthworms under oxytetracycline stress, while Proteobacteria and Firmicutes were dominant bacterial phyla in soil. Bacteriodetes and Firmicutes in earthworms worked synergistically with catalase (CAT) and glutathione peroxidase (GPX) in oxidative stress responses. In soil, Actinobacteria, Verrucomicrobia, and Spirochaeta synergistically resisted oxytetracycline stress alongside peroxidase (POD) and glutathione S-transferase (GST). Earthworm mucus played a crucial role in this synergistic resistance. These findings provide a scientific and experimental basis for assessing the ecological safety risks of antibiotic-contaminated soil.