The present invention is related to an isolated chemolithotrophic bacterium belonging to species Acidithiobacillus thiooxidans named Licanantay, deposited in Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH-DSMZ with number DSM 17318, and its use in pure form or in mixtures that contains it for bioleaching processes of minerals or sulfured metallic species concentrates. This Licanantay strain DSM 17318 has sulfur-oxidizing activity in both primary and secondary sulfured minerals, especially in the case of chalcopyrite, covellite, bornite, chalcocite, enargite and tennantite.