Cheryl Marie Cordeiro
Research Scientist
(+47) 413 42 894
cheryl.cordeiro@nibio.no
Place
Ås O43
Visiting address
Oluf Thesens vei 43, 1433 Ås
Authors
Xiaoyu Xu Yuang Cao Suli Zhi Jiahua Liu Cheryl Marie Cordeiro Erik Sindhøj Han Wang Keqiang ZhangAbstract
Microalgae exhibit unique advantages in ARG removal, yet their growth and efficacy are often constrained by complex organic matter and microorganisms in wastewater. To address this issue, this study employed chemical pretreatment to synergistically enhance microalgal treatment and, for the first time, developed a novel coupled process to tackle ARGs in livestock wastewater. The results indicate that low-chlorine (1 mg/L) pretreatment combined with the indigenous filamentous alga (S2) significantly removed pollutants (TN: 81.50%, COD: 70.71%) and reduced the total abundance of ARGs by 81.73%. The core mechanism lies in low-chlorine pretreatment shaping a mutually beneficial algae-bacteria system, which achieves efficient ARG control by altering the host bacterial. The study formalized the operating condition with a multi-objective desirability index combining nutrient removal, ARG reduction, and algal growth, which identified 1 mg/L as the overall optimum. The combined treatment process at a low chlorine dosage demonstrated both high efficiency and feasibility, providing an innovative strategy for livestock wastewater treatment.
Authors
Han Wang Keqiang Zhang Muheng Liu Shenwei Cheng Cheryl Marie Cordeiro Erik Sindhøj Junfeng Liang Yuanfang Zeng Shizhou Shen Suli ZhiAbstract
Background: Manure-amended agricultural soil is a critical reservoir of antibiotic resistance genes (ARGs), posing escalating threats to environmental health and food safety. However, the temporal trajectories of ARG prevalence throughout the complete reproductive cycle of cash crops, and their mechanistic linkages with fertilization regimes and microbial community succession, remain inadequately understood. Methods: To bridge this knowledge gap, we conducted an in situ field experiment over the entire growth period of Chinese cabbage at a long-term manure-amended farm in Tianjin, China. Six contrasting fertilization strategies were evaluated: unfertilized control (CK1), unfertilized baseline control (CK2), traditional full-rate combined manure–chemical fertilization (TF), traditional half-rate combined manure–chemical fertilization (T1), half-dose sole manure fertilizer (T2), and half-dose sole chemical fertilizer only (T3). Results: Our results demonstrated that ARG abundance and associated mobile genetic elements (MGEs) exhibited a pronounced transient surge immediately post-fertilization, yet reverted to baseline levels by harvest, revealing a tangible resilience of the soil resistome. Notably, the optimized half-organic fertilization (T2) effectively curtailed the proliferation of manure-derived pathogenic taxa while preserving beneficial keystone phyla (e.g., Acidobacteria and Proteobacteria), indicating a trade-off between nutrient provisioning and ecological filtering. Co-occurrence network analysis further identified MB-A2-108, Saccharimonadales, and Rokubacteriales as pivotal hosts for multidrug-resistant ARGs, underscoring that microbial interspecific interactions—rather than taxonomic richness alone—are the primary drivers of resistome succession. Quantitative risk assessment confirmed that the T2 regimen reduced the composite ARG contamination index (CFzone) by 25% relative to conventional full fertilization (TF), while maintaining comparable cabbage yields. Conclusions: Collectively, our findings advocate for precision organic fertilization as a nature-based solution that synchronizes nutrient supply with crop demand, curtails ARG propagation, and mitigates long-term agroecological risks.
Authors
Yuang Cao Zhuowu Li Xiaoyu Xu Cheryl Marie Cordeiro Jiahua Liu Keqiang Zhang Lianzhu Du Suli ZhiAbstract
The spread of antibiotic resistance genes (ARGs) in livestock and poultry wastewater poses a serious threat to the ecological environment and public health. This study compared the effects of biochar (BC), ferrous sulfate (FS), ferrous sulfate-modified biochar (FC), a physical mixture of ferrous sulfate and biochar (F_C), and sulfuric acid (HS) on ARG dynamics and nitrogen metabolism during the 60-day storage and fermentation of pig manure slurry. The results showed that single treatments (BC or FS) had limited ARG-removal efficiency. Compared with the control, the F_C treatment maintained higher total nitrogen (TN) levels (up to 2.42 mg/g in F_C3) while contributing to ARG reduction; however, its ARG-removal performance was not consistently superior to that of all other treatments. Although HS inhibited some ARGs, strong acidification altered the microbial community structure and may have disrupted ecological stability. Metagenomic analysis revealed that multidrug, peptide, and glycopeptide ARGs were dominant (approximately 80%) and were significantly positively correlated with key nitrogen-metabolism genes (e.g., nxrAB and nasAB, p < 0.01), suggesting a link between nitrogen cycling and ARG dissemination. Overall, the physical mixing of biochar and ferrous sulfate shows potential as a practical strategy for jointly regulating ARG dynamics and nitrogen transformation during pig manure slurry storage and fermentation, but further optimisation and validation are needed before field-scale application.