A genome catalogue of mercury-methylating bacteria and archaea from sediments of a boreal river facing human disturbances

Methyl mercury is a toxic compound produced by anaerobic microbes that biomagnifies in aquatic food webs, impacting animal and human health. Genome-based explorations of Hg methylators remain limited, particularly in the context of river ecosystems. To fill this knowledge gap, we created a genome catalogue of putative Hg-methylating microorganisms (based on the presence of hgcAB) from the sediments of a river impacted by two run-of-river hydroelectric dams, logging, and a wildfire. By using genome-resolved metagenomics, we uncovered a unique and diverse assemblage of Hg methylators dominated by members of the metabolically versatile Bacteroidota and particularly enriched in butyrate fermentative microbes. By comparing diversity and abundance of Hg methylators between sites that were subjected to different disturbances, we found that ongoing disturbances, such as input of organic matter related to logging activities, were particularly favorable to the establishment of a Hg-methylating ni..., Detailed methods are described in associated publication., , # Metagenome-assembled genomes catalogue from sediments of a boreal river facing human disturbances

The metagenome-assembled genomes (MAGs) included in this catalogue were generated from six combined assembly corresponding to the six sampling sites from which sediment cores were collected along the St. Maurice River. This repository contains contigs, amino acid sequences and genome features of the 850 MAGs that comprise this catalogue.

## Contact information

Address correspondence to David A. Walsh, .

## Description of the data and file structure

The MAGs in this catalogue underwent quality filtering based on contamination and completeness, and only high and medium-quality MAGs were retained (< 10% contamination and > 50% completeness). They were then dereplicated at ≥95% average nucleotide identity (ANI), after which only the best species representative were kept.

Each compressed folder represent different information included in this catalogue, and contain one file per M...