Enrichment and Isolation of Acidophilic Microorganisms from Sediments of Gold Mine Waste Leachate
Microorganisms living in acidic environments associated with various types of mining wastes can be used for bioremediation of acid mine drainage (AMD) and related waste streams. We studied microbial diversity of the acidic sediments of a leachate puddle at the basement of a waste rock pile from gold mining in abandoned gold deposit in Martiga (Kemerovo region, West Siberia, Russia). The enrichments were established from four sediment samples with a pH ranging from 2.29 to 6.16. The enrichments cultures were set up at aerobic and anaerobic conditions. Pure cultures of bacteria involved in iron and sulfur oxidation were isolated. The isolated iron- and sulfur-oxidizing cultures were affiliated with Acidithiobacillus and Acidocella genera as was revealed by 16S rRNA gene sequencing. Strains of Desulfosporosinus -like spore-forming bacteria were isolated under anaerobic conditions. The pure culture isolates physiological and biochemical characterization is underway, which will provide new knowledge of AMD formation and natural processes of metal attenuation. The strains can also be prospective agents for use in bioleaching and bioremediation processes.