title: Copper bioaccumulation by the actinobacterium Amycolatopsis sp. AB0.
abstract: Amycolatopsis sp. AB0, a copper resistant actinobacterium isolated from polluted sediments, has shown high copper specific biopsortion ability (25 mg g(-1)). Two approaches were used to confirm metal accumulation in growing cells of Amycolatopsis sp. AB0; we performed subcellular fractioning assays which showed that the retained copper was associated with the extra-cellular fraction (exopolymer, 40%), but mainly within the cells. Intracellular distribution of copper was: 86% in the cytosolic fraction, 11% at the cell wall and 3% associated with the ribosome/membrane fraction. Its copper bioaccumulation ability was corroborated by using silver enhanced staining of copper with the Timm's reagent technique, which has not been used to detect metal deposits in bacteria before. In addition, we constructed specific oligonucleotides for targeting genes coding for copper P-Type ATPases that could be involved in the copper uptake ability of this strain. A 607 bp DNA fragment was amplified and sequenced from Amycolatopsis sp AB0. BLAST search analysis showed 71% protein homology of the deduced sequence with a putative cation-transporting ATPase of Nocardia farcinica and 65% with a copper translocating ATPase of Mycobacterium flavescens. To our knowledge this is the first report of the presence of copper P-type ATPase genes in the Amycolotopsis genus.
authors.affiliation: Pilot Plant of Industrial and Microbiological Processes (PROIMI), CONICET, Av. Belgrano y Pasaje Caseros, Tucumán, Argentina.
authors.forename: Virginia Helena
authors.initials: VH
authors.lastname: Albarracín
authors.forename: Beatriz
authors.initials: B
authors.lastname: Winik
authors.forename: Erika
authors.initials: E
authors.lastname: Kothe
authors.forename: María Julia
authors.initials: MJ
authors.lastname: Amoroso
authors.forename: Carlos Mauricio
authors.initials: CM
authors.lastname: Abate
mesh_terms: D000192:Actinomycetales / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D000251:Adenosine Triphosphatases / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D027682:Cation Transport Proteins / Q000235:genetics* / Q000378:metabolism; D003300:Copper / Q000378:metabolism*; D000073840:Copper-Transporting ATPases; D004269:DNA, Bacterial / Q000235:genetics; D018390:Gene Targeting; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D001426:Bacterial Proteins; D027682:Cation Transport Proteins; D004269:DNA, Bacterial; D003300:Copper; D000251:Adenosine Triphosphatases; D000073840:Copper-Transporting ATPases