zixibacteria zixibacteria zixibacteria is a bacterial phylum with candidate status, meaning it had no cultured representatives. it is a member of the fcb group zixibacteria scientific classification domain: bacteria (unranked): fcb group phylum: zixibacteriacastelle et al. 2013 zixibacteria was proposed as a bacterial phylum following the recovery of a genome from representative rbg-1. this genome was recovered using genome-resolved metagenomics from sediment samples of an aquifer adjacent to the colorado river (co, usa) and was suggestive of metabolically versatility, which is presumably requisite for life in a rapidly changing environment such as aquifer sediments since being proposed as a phylum in 2013, members of the zixibacteria phylum have been detected in a variety of other environments (sometimes retroactively), including subsurface sediments (wa, usa), estuary water (nc, usa), moonmilk cave deposits (comblain-au-pont, belgium), and deep subsurface fracture fluids from a gold mine (sd, usa)