Copper bioaccumulation by the actinobacterium Amycolatopsis sp. AB0.

ALBARRACÍN, V.H.; WINIK B.; KOTHE E.; AMOROSO M.J.; ABATE C.M.

JOURNAL OF BASIC MICROBIOLOGY

WILEY-VCH Verlag GmbH & Co. KGaA

Año: 2008

0233-111X

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 Amycolatopsis genus.