Microbial diversity in extreme environments. Applications on the remediation and recovery of metals

DONATI EDGARDO; CASTRO CAMILA; BERNARDELLI CECILIA; MUÑOZ ANDREA; WILLIS PORATTI GRACIANA; PLAZA CAZÓN JOSEFINA; HIPPERDINGER MARCELA; URBIETA M. SOFÍA

Leipzig

Simposio; 17th International Symposium on Microbial Ecology; 2018

ISME

Abandoned metal mines and some geothermal/volcanic areas containing great heavy metal concentrations are attractive environments for searching new microbial species with biotechnological applications. The extremophilic microorganisms found there have metabolic activities and/or have developed specific strategies to survive that can be used in processes for recovering or remediating heavy metals. The main goal of our research team is assessing the prokaryotic diversity in those extreme areas to achieve microbial species or consortia capable of being used in biotechnological applications as biomining or bioremediation of metal polluted environments. In this case we show the results of prokaryotic diversity in two geothermal areas, Copahue and Domuyo (Neuquén, Argentina) and in three different environments associated with mining activities, Pan de Azucar mine (Jujuy, Argentina), Castaño Antiguo mine (San Juan, Argentina), and Amarillo River (Famatina Belt, La Rioja, Argentina). In each environment, three different approaches, enrichment to isolate autochthonous microorganisms, 16S rRNA gene-based analysis including metagenomic and FISH, were used. Dominant prokaryotes were chemolithoautotrophic or mixotrophic, mainly sulfur and/or iron oxidizing bacteria and archaea; some new sequences of archaea and bacteria were detected and also some new species could be isolated. Within the biotechnological applications, some isolates were capable of solubilizing metals from minerals including the total copper solubilization from chalcopyrite (a refractory copper mineral) by an isolate of a new species of Acidianus growing at 65ºC. Some microbial communities isolated showed the ability to precipitate metals even at low pH values and to reduce hexavalent chromium to the less toxic trivalent chromium.