Effect of composted pig manure, biochar, and their combination on antibiotic resistome dissipation in swine wastewater-treated soil. (15th April 2023)

• Record Type: Journal Article
• Authors: Sun, Likun; Tang, Defu; Tai, Xisheng; Wang, Jiali; Long, Min; Xian, Tingting; Jia, Haofan; Wu, Renfei; Ma, Yongqi; Jiang, Yunpeng
• Is Part Of: Environmental pollution. Volume 323(2023)
• Publication Date: 2023-04-15
• Subjects: Antibiotic resistance gene -- Composted manure -- Biochar -- Swine wastewater-treated soil -- Dissipation; ANOSIM analyses of similarities -- ANOVA analysis of variance -- AK available potassium -- AP available phosphorus -- ARG antibiotic resistance gene -- BS bulk soil -- EC electrical conductivity -- HGT horizontal gene transfer -- MGE mobile genetic element -- MRG multidrug resistance genes -- NMDS non-metric multi-dimensional scaling -- OLS ordinary least squares -- OTU operational taxonomic units -- RE root endophytes -- RS rhizosphere soil -- SEM structural equation modelling; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2023.121323
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The prevalence of antibiotic resistance genes (ARGs), owing to irrigation using untreated swine wastewater, in vegetable-cultivated soils around swine farms poses severe threats to human health. Furthermore, at the field scale, the remediation of such soils is still challenging. Therefore, here, we performed field-scale experiments involving the cultivation of Brassica pekinensis in a swine wastewater-treated soil amended with composted pig manure, biochar, or their combination. Specifically, the ARG and mobile genetic element (MGE) profiles of bulk soil (BS), rhizosphere soil (RS), and root endophyte (RE) samples were examined using high-throughput quantitative polymerase chain reaction. In total, 117 ARGs and 22 MGEs were detected. Moreover, we observed that soil amendment using composted pig manure, biochar, or their combination decreased the absolute abundance of ARGs in BS and RE after 90 days of treatment. However, the decrease in the abundance of ARGs in RS was not significant. We also observed that the manure and biochar co-application showed a minimal synergistic effect. To clarify this observation, we performed network and Spearman correlation analyses and used structure equation models to explore the correlations among ARGs, MGEs, bacterial composition, and soil properties. The results revealed that the soil amendments reduced the abundances of MGEs and potential ARG-carrying bacteria. Additionally, weakened horizontal gene transfer was responsible for the dissipation of ARGs. Thus, our results indicate that composted manure application, with or without biochar, is a useful strategy for soil nutrient supplementation and alleviating farmland ARG pollution, providing a justification for using an alternative to the common agricultural practice of treating the soil using only untreated swine wastewater. Additionally, our results are important in the context of soil health for sustainable agriculture. Graphical abstract: Image 1 Highlights: Soil amendment by manure/biochar reduced antibiotic resistance gene (ARG) abundance. Weakened horizontal gene transfer was responsible for ARG dissipation. Co-application of composted manure and biochar had a minimal synergistic effect.