[1] In 2006, representatives of Gracilibacteria were recovered from a hypersaline microbial mat from Guerrero Negro, Baja California Sur, Mexico and proposed as a new phylum "GN02".
[2] The name "Gracilibacteria" was proposed for the BD1-5/GN02 lineage in 2013, based on a substantial expansion of the genomic representation of this phylum.
[3][4] The first Gracilibacteria genome was recovered from an acetate-amended aquifer (Rifle, CO, USA) using culture-independent, genome-resolved metagenomic techniques in 2012.
[5] Genomic analyses suggest that members of the Gracilibacteria phylum have limited metabolisms and are likely symbionts or endosymbionts.
[3] Members of Gracilibacteria use an alternative genetic code in which UGA encodes the glycine amino acid instead of a stop codon[6]