Antibiotic contamination stimulates microbial methylmercury synthesis in rice paddies
Abstract
Antibiotic residues are now widespread in agricultural soils, yet their influence on microbe-mediated mercury (Hg) transformations and associated risks is poorly understood. Here, we demonstrate that fluoroquinolone (FQ) antibiotics enhance the production of neurotoxic methylmercury (MeHg) in paddy soils by selectively altering microbial metabolic activity. In 40 paddy soils from China’s major rice-growing regions, FQ addition at 10 mg kg ⁻¹ increased MeHg content by 2.9%–19.7% after 21 days of incubation. Metabolic inhibition and microcosm experiments revealed that this increase stemmed primarily from stimulated microbial Hg methylation, rather than inhibited MeHg demethylation. Sulfate-reducing bacteria (SRB) dominated this process since inhibiting sulfate reduction decreased FQ-induced Hg methylation by 31%–75%. Integrated microbiome and functional prediction based on soil microbial communities and metagenomic analyses of enriched SRB consortia further identified hgcA -carrying SRB as the key methylators. FQ exposure selectively suppressed competing microbial groups while promoting metabolically active, antibiotic-tolerant SRB, particularly those using the reductive acetyl-CoA pathway, thereby elevating Hg methylation activity without significantly changing methylator abundance or community structure. Together, these findings reveal that widespread antibiotic contamination amplifies Hg risks in soils via tolerant microbial communities, potentially representing a hidden yet critical link between emerging contaminants, heavy metals, and food safety.
Related
- Metagenomic evidence for climate-associated variation in microbial methylmercury production across peatlands
- Bacterial contamination, antibiotic resistance, and biofilm formation on operating rooms surfaces at Jimma Medical Center, Southwest Ethiopia
- Urbanization Impacts the Environmental Microbial Community and Its Antibiotic Phenotypic Resistance Potential by Reshaping the Diversity and Network Complexity
- Unlocking Iridium Chemical Space for Antibiotic Discovery through One-Pot Combinatorial Synthesis in a Direct-to-Biology Approach.
- Timing of First Systemic Antibiotic Administration and Risk of Deep Infection in Adults with Open Long-Bone Fractures: A Systematic Review and Threshold-Specific Evidence Synthesis
BibTeX
@article{li2026antibiotic,
title = {{Antibiotic contamination stimulates microbial methylmercury synthesis in rice paddies}},
author = {Hailong Li and Xiangzhen Li and Xiao Zhang and Wenli Tang and Jingli Liu and Ri-Qing Yu and Christopher Rensing and Yi Luo and Xiaolong Wang and Juntao Xia and Ya-Nan Yang and Yang Hu and Hao-Ran Zhao and Yujiao Liu and Mengjie Wu and Chengjun Li and Lin Xiao and Huan Zhong},
journal = {Nature Communications},
year = {2026},
month = oct,
doi = {10.1038/s41467-026-79083-7},
url = {https://www.nature.com/articles/s41467-026-79083-7},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Antibiotic contamination stimulates microbial methylmercury synthesis in rice paddies
AU - Hailong Li
AU - Xiangzhen Li
AU - Xiao Zhang
AU - Wenli Tang
AU - Jingli Liu
AU - Ri-Qing Yu
AU - Christopher Rensing
AU - Yi Luo
AU - Xiaolong Wang
AU - Juntao Xia
AU - Ya-Nan Yang
AU - Yang Hu
AU - Hao-Ran Zhao
AU - Yujiao Liu
AU - Mengjie Wu
AU - Chengjun Li
AU - Lin Xiao
AU - Huan Zhong
PY - 2026
DA - 2026/10/27
JO - Nature Communications
DO - 10.1038/s41467-026-79083-7
UR - https://www.nature.com/articles/s41467-026-79083-7
AB - Antibiotic residues are now widespread in agricultural soils, yet their influence on microbe-mediated mercury (Hg) transformations and associated risks is poorly understood. Here, we demonstrate that fluoroquinolone (FQ) antibiotics enhance the production of neurotoxic methylmercury (MeHg) in paddy soils by selectively altering microbial metabolic activity. In 40 paddy soils from China’s major rice-growing regions, FQ addition at 10 mg kg ⁻¹ increased MeHg content by 2.9%–19.7% after 21 days of incubation. Metabolic inhibition and microcosm experiments revealed that this increase stemmed primarily from stimulated microbial Hg methylation, rather than inhibited MeHg demethylation. Sulfate-reducing bacteria (SRB) dominated this process since inhibiting sulfate reduction decreased FQ-induced Hg methylation by 31%–75%. Integrated microbiome and functional prediction based on soil microbial communities and metagenomic analyses of enriched SRB consortia further identified hgcA -carrying SRB as the key methylators. FQ exposure selectively suppressed competing microbial groups while promoting metabolically active, antibiotic-tolerant SRB, particularly those using the reductive acetyl-CoA pathway, thereby elevating Hg methylation activity without significantly changing methylator abundance or community structure. Together, these findings reveal that widespread antibiotic contamination amplifies Hg risks in soils via tolerant microbial communities, potentially representing a hidden yet critical link between emerging contaminants, heavy metals, and food safety.
SN - 2041-1723
ER -