Microorganisms found in a metal-impacted stream, Blackbird Creek, Idaho

Iron oxidizing microorganisms play a key role in the iron (Fe) cycle. In metal-rich environments, microorganisms catalyze Fe oxidation and subsequent precipitation reactions, thus forming biogenic minerals. This process occurs naturally, but can also be human induced in cases of metal-contaminated water remediation efforts. Iron-oxidizing bacteria (FeOB) that live in neutral pH environments are highly specialized because they have to compete with the rapid chemical oxidation of Fe²⁺ that occurs at neutral pH. The primary research objective was to determine what FeOB can be detected in the artificially neutral, Fe-rich environment of Blackbird Creek that flows from the retired Blackbird Mine in Cobalt, Idaho. The bacteria sequences from two sample sites were classified using the 16S rRNA gene. The culture-independent study indicated that neutrophilic FeOB were in fact present in Blackbird Creek, along with a variety of aquatic and soil bacteria. FeOB interactions with Fe have significant implications for environmental cleanup and acid mine drainage (AMD) remediation, as the bacteria help to remove dissolved metals from solution through biomineralization.