biostudies-literatureUnknown17(3)Zhang CJMethylmercury (MeHg) is a potent neurotoxin that bioaccumulates along food chains. The conversion of MeHg from mercury (Hg) is mediated by a variety of anaerobic microorganisms carrying hgcAB genes. Mangrove sediments are potential hotspots of microbial Hg methylation; however, the microorganisms responsible for Hg methylation are poorly understood. Here, we conducted metagenomic and metatranscriptomic analyses to investigate the diversity and distribution of putative microbial Hg-methylators in mangrove ecosystems. The highest hgcA abundance and expression occurred in surface sediments in Shenzhen, where the highest MeHg concentration was also observed. We reconstructed 157 metagenome-assembled genomes (MAGs) carrying hgcA and identified several putative novel Hg-methylators, including onThe ISME journal478-485https://www.ebi.ac.uk/biostudies/studies/S-EPMC9938162biostudies-literaturePotential for mercury methylation by Asgard archaea in mangrove sediments.PMC9938162Liu YPan JCha GCai MLu ZLiu YRZhang CJLi MZhou XQfalsePotential for mercury methylation by Asgard archaea in mangrove sediments.Methylmercury (MeHg) is a potent neurotoxin that bioaccumulates along food chains. The conversion of MeHg from mercury (Hg) is mediated by a variety of anaerobic microorganisms carrying hgcAB genes. Mangrove sediments are potential hotspots of microbial Hg methylation; however, the microorganisms responsible for Hg methylation are poorly understood. Here, we conducted metagenomic and metatranscriptomic analyses to investigate the diversity and distribution of putative microbial Hg-methylators in mangrove ecosystems. The highest hgcA abundance and expression occurred in surface sediments in Shenzhen, where the highest MeHg concentration was also observed. We reconstructed 157 metagenome-assembled genomes (MAGs) carrying hgcA and identified several putative novel Hg-methylators, including on2023-01-01T00:00:00Z2023 Mar2026-03-27T16:33:27.708Z2025-04-07T04:28:16.434ZS-EPMC99381623663953810.1038/s41396-023-01360-w