ABSTRACT
The genome of Melioribacter roseus, one of two members of the recently described phylum Ignavibacteriae, was searched for the 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) was.probably involved in assembly of the copper-containing cytochrome c oxidase, while two others (MROS_0327 and MROS_0791) probably carried 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 those of Bacteroidetes and Chlorobi.
Subject(s)
Bacterial Proteins/chemistry , Bacteroidetes/classification , Chlorobi/classification , Copper/metabolism , Genome, Bacterial , Oxidoreductases/chemistry , Phylogeny , Adenosine Triphosphatases/chemistry , Adenosine Triphosphatases/genetics , Adenosine Triphosphatases/metabolism , Amino Acid Sequence , Anaerobiosis/physiology , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Bacteroidetes/genetics , Bacteroidetes/metabolism , Carrier Proteins/chemistry , Carrier Proteins/genetics , Carrier Proteins/metabolism , Chlorobi/genetics , Chlorobi/metabolism , Coenzymes/chemistry , Coenzymes/metabolism , Gene Expression , Homeostasis/physiology , Hot Temperature , Molecular Sequence Data , Oxidoreductases/genetics , Oxidoreductases/metabolism , Protein Isoforms/chemistry , Protein Isoforms/genetics , Protein Isoforms/metabolism , Sequence Homology, Amino AcidABSTRACT
Dissimilatory sulfate reduction plays an important role in removal of dissolved metals from acidic mine waters. Although this process was convincingly shown to occur in acidic waste of metal recovery, few isolates of acid-tolerant sulfate rducers are known. We isolated a new acidophilic sulfidogen, strain BG, from the oxidized acidic waste of the Bom-Gorkhon tungsten deposit, Transbaikalia, Russia. Phylogenetic analysis of its 16S rRNA gene sequence made it possible to identify it as a member of the genus Desulfosporosinus. Unlike other known acidophilic sulfate reducers of this genus, strain BG was tolerant to high copper concentrations (up to 5 g/L), could grow on organic acids at low ambient pH, and formed crystalline copper sulfides (covellite and chalcopyrite). Molecular analysis of the phenotypes predominating in oxidized waste and in enrichment cultures confirmed the presence of various Desulfosporosinus strains.