Cultivation-dependent and independent approaches for determining prokaryotic diverstiy in acid mine drainage.

BENITEZ L.; PLAZA CAZON J.; DONATI E.R.; BERNARDELLI C.; MUÑOZ M.A.; URBIETA M.S.

Congreso; FEMS 2017; 2017

Sulfide ores usually rich in heavy metals are a potential source for acid mine/rock drainage (AMD/ARD) which can cause severe contamination of surface and groundwater, also impacting on soils and plants constituting a serious environmental problem. AMD/ARD are produced when metal sulfides ?mainly pyrite- are exposed to air and water. Although the process can occur under abiotic conditions, microbial activity can highly increase the rate of acid drainage generation. In order to prevent and/or remediate AMD/ARD, the native microbial communities must be assessed. It is widely accepted that culture-independent methods have many advantages on the traditional isolation techniques for microbial community analysis. However, for determining the role and the impact of indigenous communities on certain processes ?like AMD/ARD generation- the contribution of cultivation approaches cannot be discarded. The aim of this work was to assess the prokaryotic diversity on the acid drainages of the Pan de Azúcar mine (Jujuy, Argentina) and Amarillo River (Famatina Belt, La Rioja, Argentina). Denaturating gel gradient electrophoresis (DGGE) and metagenomic were used to determine the structure of the microbial communities. Based on such results cultivation techniques were used to isolate microorganisms, although only a limited number of the predicted species were obtained. In addition, the isolates were tested on samples of tailings from Pan de Azucar mine and on water samples from Amarillo River. The results of our study show a decisive role of the species isolated on the AMD/ARD generation and on the geochemical characteristics of both acid drainages.