Isolation and phylogenetic characterization of biomining microorganisms from actual mine operations in northern Argentina

AGUSTINA AMAR; CAMILA CASTRO; MARCELA HIPPERDINGER; CRISTINA COSTA; EDGARDO DONATI

Simposio; 2nd International Symposium on Extreme Ecosystems and Extremophiles Organisms; 2019

In the Argentinean province of Jujuy, mine operations involving extraction of silver, zinc and lead are currently carried out at Chinchillas mine. This new project is located in the Andean region at 4200 meters over the sea level, 40 km far from Pirquitas mine, an old mineral site that presents shallow acid mine drainages. Also, River Pircas that receives contribution from Pirquitas, presents acid mine dreinage. The present work involved isolation and phylogenetic characterization of biomining microorganisms from both Chinchillas and Pirquitas. Samples 1, 2 and 3 were obtained from acid waters of Pirquitas. Samples 4 and 5 were from minerals of Chinchillas, very low grade ore (0.2% zinc) and dump ore (specially separated in stocks for it risk of acid drainage generation), respectively. The aim of this study was to identify naturally occurring bacteria with biomining activity, that could be used for biotechnological purposes such as bioremediation of acid mine drainage or bioleaching from low grade ore. All the samples were enriched in selective media with basal salt medium MAC supplemented with ferrous sulfate for iron oxidizers, ferrous sulfate and yeast extract for mixotrophs, sulfur for sulfur oxidizers, sulfur and yeast extract for mixotrophs. All the cultures were kept at 30 ºC for the isolation of mesophiles. Samples from Chinchillas didn?t show growth of any kind of bacteria, while all the enrichments from Pirquitas presented significant growth. The 16S rRNA gene was amplified in all the isolated bacteria in order to identify the genus/specie.