Interaction of acid mine drainage with waters and sediments of West Squaw Creek in the West Shasta Mining District, California

1987 ◽  
Vol 21 (4) ◽  
pp. 388-396 ◽  
Author(s):  
Lorraine H. Filipek ◽  
D. Kirk. Nordstrom ◽  
Walter H. Ficklin
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Mining District ◽  
The West ◽  
Acid Mine

scholarly journals Mixotrophic Iron-Oxidizing Thiomonas Isolates from an Acid Mine Drainage-Affected Creek

2020 ◽  
Vol 86 (24) ◽  
Author(s):  
Denise M. Akob ◽  
Michelle Hallenbeck ◽  
Felix Beulig ◽  
Maria Fabisch ◽  
Kirsten Küsel ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Iron Oxidation ◽  
Specific Gene ◽  
Mining District ◽  
Content Type ◽  
Acid Mine ◽  
Metal Precipitation ◽  
Genetic Potential ◽  
Fe Oxidation

ABSTRACT Natural attenuation of heavy metals occurs via coupled microbial iron cycling and metal precipitation in creeks impacted by acid mine drainage (AMD). Here, we describe the isolation, characterization, and genomic sequencing of two iron-oxidizing bacteria (FeOB) species: Thiomonas ferrovorans FB-6 and Thiomonas metallidurans FB-Cd, isolated from slightly acidic (pH 6.3), Fe-rich, AMD-impacted creek sediments. These strains precipitated amorphous iron oxides, lepidocrocite, goethite, and magnetite or maghemite and grew at a pH optimum of 5.5. While Thiomonas spp. are known as mixotrophic sulfur oxidizers and As oxidizers, the FB strains oxidized Fe, which suggests they can efficiently remove Fe and other metals via coprecipitation. Previous evidence for Thiomonas sp. Fe oxidation is largely ambiguous, possibly because of difficulty demonstrating Fe oxidation in heterotrophic/mixotrophic organisms. Therefore, we also conducted a genomic analysis to identify genetic mechanisms of Fe oxidation, other metal transformations, and additional adaptations, comparing the two FB strain genomes with 12 other Thiomonas genomes. The FB strains fall within a relatively novel group of Thiomonas strains that includes another strain (b6) with solid evidence of Fe oxidation. Most Thiomonas isolates, including the FB strains, have the putative iron oxidation gene cyc2, but only the two FB strains possess the putative Fe oxidase genes mtoAB. The two FB strain genomes contain the highest numbers of strain-specific gene clusters, greatly increasing the known Thiomonas genetic potential. Our results revealed that the FB strains are two distinct novel species of Thiomonas with the genetic potential for bioremediation of AMD via iron oxidation. IMPORTANCE As AMD moves through the environment, it impacts aquatic ecosystems, but at the same time, these ecosystems can naturally attenuate contaminated waters via acid neutralization and catalyzing metal precipitation. This is the case in the former Ronneburg uranium-mining district, where AMD impacts creek sediments. We isolated and characterized two iron-oxidizing Thiomonas species that are mildly acidophilic to neutrophilic and that have two genetic pathways for iron oxidation. These Thiomonas species are well positioned to naturally attenuate AMD as it discharges across the landscape.

Controlling acid mine drainage from the Ficher Mining District, Oklahoma, United States

1982 ◽  
Vol 1 (1) ◽  
pp. 45-52 ◽  
Author(s):  
R. Bruce Sheibach ◽  
Roy E. Williams ◽  
Benjamin R. Genes
Keyword(s):  
United States ◽  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Mining District ◽  
Acid Mine
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