Microbial diversity at the moderate acidic stage in three different sulfidic mine tailings dumps generating acid mine drainage

Abstract In freshly deposited sulfidic mine tailings the pH is alkaline or circumneutral. Due to pyrite or pyrrhotite oxidation the pH is dropping over time to pH values Proteobacteria and Firmicutes were overall the most abundant phyla in the clone libraries. Acidobacteria, Actinobacteria, Bacteroidetes , and Nitrospira occurred less frequently. The found microbial communities were completely different to microbial communities in tailings at