Mersorcium is an international network that originates from the Meta-Hg working group, created in 2020 by Eric Capo, a collaborative project aiming to promote best practices in the detection and identification of Hg-cycling genes from environmental genomic data. The first outcome of the Meta-Hg working group is the release of the version 1 Hg-MATE database, a hgcAB gene catalogue (Gionfriddo et al. 2021). As a continuation to this work, researchers from Mersorcium aim to augment this database with information about merA and merB genes.