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.

scholarly journals Efficient Low-pH Iron Removal by a Microbial Iron Oxide Mound Ecosystem at Scalp Level Run

2017 ◽  
Vol 83 (7) ◽  
Author(s):  
Christen L. Grettenberger ◽  
Alexandra R. Pearce ◽  
Kyle J. Bibby ◽  
Daniel S. Jones ◽  
William D. Burgos ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Bacterial Community ◽  
Microbial Communities ◽  
Mine Drainage ◽  
Iron Oxidation ◽  
Cost Effective ◽  
Low Ph ◽  
Content Type ◽  
Oxidation Rates ◽  
Acid Mine

ABSTRACT Acid mine drainage (AMD) is a major environmental problem affecting tens of thousands of kilometers of waterways worldwide. Passive bioremediation of AMD relies on microbial communities to oxidize and remove iron from the system; however, iron oxidation rates in AMD environments are highly variable among sites. At Scalp Level Run (Cambria County, PA), first-order iron oxidation rates are 10 times greater than at other coal-associated iron mounds in the Appalachians. We examined the bacterial community at Scalp Level Run to determine whether a unique community is responsible for the rapid iron oxidation rate. Despite strong geochemical gradients, including a >10-fold change in the concentration of ferrous iron from 57.3 mg/liter at the emergence to 2.5 mg/liter at the base of the coal tailings pile, the bacterial community composition was nearly constant with distance from the spring outflow. Scalp Level Run contains many of the same taxa present in other AMD sites, but the community is dominated by two strains of Ferrovum myxofaciens, a species that is associated with high rates of Fe(II) oxidation in laboratory studies. IMPORTANCE Acid mine drainage pollutes more than 19,300 km of rivers and streams and 72,000 ha of lakes worldwide. Remediation is frequently ineffective and costly, upwards of $100 billion globally and nearly $5 billion in Pennsylvania alone. Microbial Fe(II) oxidation is more efficient than abiotic Fe(II) oxidation at low pH (P. C. Singer and W. Stumm, Science 167:1121–1123, 1970, https://doi.org/10.1126/science.167.3921.1121 ). Therefore, AMD bioremediation could harness microbial Fe(II) oxidation to fuel more-cost-effective treatments. Advances will require a deeper understanding of the ecology of Fe(II)-oxidizing microbial communities and the factors that control their distribution and rates of Fe(II) oxidation. We investigated bacterial communities that inhabit an AMD site with rapid Fe(II) oxidation and found that they were dominated by two operational taxonomic units (OTUs) of Ferrovum myxofaciens, a taxon associated with high laboratory rates of iron oxidation. This research represents a step forward in identifying taxa that can be used to enhance cost-effective AMD bioremediation.

scholarly journals Phylogeny of Microorganisms Populating a Thick, Subaerial, Predominantly Lithotrophic Biofilm at an Extreme Acid Mine Drainage Site

2000 ◽  
Vol 66 (9) ◽  
pp. 3842-3849 ◽  
Author(s):  
Philip L. Bond ◽  
Steven P. Smriga ◽  
Jillian F. Banfield
Keyword(s):  
Acid Mine Drainage ◽  
16S Rrna ◽  
New Genus ◽  
Mine Drainage ◽  
Iron Oxidation ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Metal Reduction ◽  
Acid Mine ◽  
Metabolic Feature

ABSTRACT An unusually thick (∼1 cm) slime developed on a slump of finely disseminated pyrite ore within an extreme acid mine drainage site at Iron Mountain, near Redding, Calif. The slime was studied over the period of 1 year. The subaerial form of the slime distinguished it from more typical submerged streamers. Phylogenetic analysis of 16S rRNA genes revealed a diversity of sequences that were mostly novel. Nearest relatives to the majority of sequences came from iron-oxidizing acidophiles, and it appears that iron oxidation is the predominant metabolic characteristic of the organisms in the slime. The most abundant of the 16S rRNA genes detected were from organisms related toLeptospirillum species. The dominant sequence (71% of clones) may represent a new genus. Sequences within theArchaea of the Thermoplasmales lineage were detected. Most of these were only distantly related to known microorganisms. Also, sequences affiliating withAcidimicrobium were detected. Some of these were closely related to “Ferromicrobium acidophilus,” and others were affiliated with a lineage only represented by environmental clones. Unexpectedly, sequences that affiliated within the delta subdivision of the Proteobacteria were detected. The predominant metabolic feature of bacteria of this subdivision is anaerobic sulfate or metal reduction. Thus, microenvironments of low redox potential possibly exist in the predominantly oxidizing environments of the slime. These results expand our knowledge of the biodiversity of acid mine drainage environments and extend our understanding of the ecology of extremely acidic systems.

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

scholarly journals Performance Evaluation of Waste Materials for the Treatment of Acid Mine Drainage to Remove Heavy Metals and Sulfate

2021 ◽  
Author(s):  
Satish Chandra Bhuyan ◽  
Subrat Kumar Bhuyan ◽  
Himanshu Bhushan Sahu
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Low Cost ◽  
Iron Oxidation ◽  
Mining Industry ◽  
Packed Bed ◽  
Cement Kiln ◽  
Acid Mine ◽  
Current Scenario ◽  
The Cost

Acid Mine Drainage (AMD) is the most severe environmental problem facing the mining sector in the current scenario because of low pH and high pollutants concentration. AMD contains a high amount of sulphate viz. pyrite, FeS2, and to a lesser extent pyrrhotite and heavy metal ions, contaminate both surface water and groundwater. To treat AMD, extensive research projects have been initiated by governments, the mining industry, universities, and research establishments. The environmental impact of AMD can be minimized at these basic levels; prevention should be taken to control the infiltration of groundwater to the pollution site and control the acid-generating process. There are some conventional active methods to treat AMD, such as compost reactor and packed bed iron-oxidation bioreactors; however, these methods have associated with costly material and high maintenance cost, which increases the cost of the entire treatment. In an alternative, the use of low-cost materials such as fly ash, metallurgical slag, zero-valent iron (ZVI), cement kiln dust (CKD), and organic waste such as peat humic agent (PHA), rice husk, and eggshell can be a valuable measure for economic viability to treat the metal-rich wastewater.

Sign in / Sign up

Export Citation Format

Share Document