The genome of Melioribacter roseus, one of the two members of the recently described phylum Ignavibacteriae, was screened for genes encoding proteins associated with copper transport or containing copper as cofactors, and the effect of Cu2+ concentration in the medium on M. roseus growth was investigated. Genomic analysis revealed a variety of copper-containing oxidoreductases in this facultative anaerobe. Three ATPases responsible for copper transport were identified. One of them (MROS_1511) is probably involved in the assembly of the copper-containing cytochrome c oxidase, while two others (MROS_0327 and MROS_0791) probably carry out a detoxification function. The presence of several copper-containing oxidoreductases and copper homeostasis systems in M. roseus is in agreement with the previously hypothesized origin of the phylum Ignavibacteriae from an aerobic ancestor common with Bacteroidetes and Chlorobi.