Resumen

SACACA C., Sonia; INIGUEZ R., Volga  y  ROULET, Marc. Diversity and distribution of sulfate-reducing bacteria at Milluni lakes sediments contaminated with acid mine drainages. BIOFARBO [online]. 2009, vol.17, n.2, pp. 39-50. ISSN 1813-5363.

The anaerobic sulphate-reducing bacteria (SRB) may play an important role in acid mine drainage mitigation, lowering sulphate concentrations derived from Acid Mine Drainage (AMD), by promoting metal sulphides precipitation and producing local alkalinity. The present study was carried out at the Milluni Lakes located in the Altiplano highlands north from La Paz city, to determine diversity and distribution of SRB. The Milluni region has accumulated mining waste as a result of unregulated heavy-metal mining since the past century. SRB subgroups distribution along a deep profile in sediments and wetlands samples contaminated with AMD of different physicochemical conditions was analyzed by PCR and nested-PCR of 16S DNAr. Results evidenced presence of SRB with defined spatial distribution in all analyzed lakes representing a wide range of physico-chemical conditions of Eh (+350 to -330 mV) and pH (10 to 2.5). Along the sediment profiles, considerable variation in SRB- distribution was evident, being Desulfovibrio-Desulfomicrobium (DSV-DMB) and Desulfococcus-Desulfonema-Desulfosarcina (DCC-DNM-DSS) the most commonly found subgroups. The variable physico-chemical conditions and lakes location to the mine may have conditioned distribution and adaptation of SRB projecting them as a potential tool for bioremediation in this region.

Palabras llave : Sulphate-reducing bacteria (SRB); Acid mine drainage (AMD); 16S rRNA gene.