Proteomic Approach of Adaptive Response to Arsenic Stress in Exiguobacterium sp. S17. An Extremophile Strain Isolate from High Altitude Andean Lake Stromatolite

CAROLINA BELFIORE; OMAR F. ORDOÑEZ; MARIA EUGENIA FARIAS

EXTREMOPHILES

SPRINGER TOKYO

Lugar: Tokyo; Año: 2013 vol. 3 p. 421 - 431

1431-0651

Abstract The North-Western part of Argentina is particularlyrich in wetlands located in the Puna in an altitudebetween 3,600 and 4,600 m above sea level. Most of thesehigh-altitude Andean lakes are inhospitable areas due toextreme habitat conditions such as high contents of toxicelements, particularly arsenic. Exiguobacterium sp. S17,isolated from stromatolites in Laguna Socompa, exhibitedremarkable tolerance to high arsenic concentration, i.e., ittolerated arsenic concentration such as 10 mM of As(III)and 150 mM of As(V). A proteomics approach was conductedto reveal the mechanisms that provide the observedoutstanding resistance of Exiguobacterium sp. S17 againstarsenic. A comparative analysis of S17, exposed andunexposed to arsenic revealed 25 differentially expressedproteins. Identification of these proteins was performed byMALDI-TOF/MS revealing upregulation of proteinsinvolved in energy metabolism, stress, transport, and inprotein synthesis being expressed under arsenic stress. Toour knowledge, this work represents the first proteomicstudy of arsenic tolerance in an Exiguobacterium strain.