The object of the invention is the plasmid pSheB, particularly a plasmid which may comprise a fragment of pSheB including the arr module and functional derivatives thereof, and strains containing such a plasmid, preferably the Shewanella sp. strain, deposited as KKP 2045p, which are capable of removing arsenic by dissolution of minerals and reduction of arsenates to arsenites. The object of the invention is also the method and the use of such bacterial strains or compositions which may comprise them, for the selective removal of arsenic from mineral resources, raw materials industry waste or soil.