Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

pH Gradient-Induced Heterogeneity of Fe(III)-Reducing Microorganisms in Coal Mining-Associated Lake Sediments

pH Gradient-Induced Heterogeneity of Fe(III)-Reducing Microorganisms in Coal Mining-Associated... pH Gradient-Induced Heterogeneity of Fe(III)-Reducing Microorganisms in Coal Mining-Associated Lake Sediments ▿ † Marco Blöthe 1 , ‡ , Denise M. Akob 2 , Joel E. Kostka 2 , Kathrin Göschel 1 , Harold L. Drake 1 and Kirsten Küsel 1 , 3 , * 1 Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany 2 Department of Oceanography, Florida State University, Tallahassee, Florida 32306 3 Limnology Research Group, Friedrich Schiller University Jena, 07743 Jena, Germany ABSTRACT Lakes formed because of coal mining are characterized by low pH and high concentrations of Fe(II) and sulfate. The anoxic sediment is often separated into an upper acidic zone (pH 3; zone I) with large amounts of reactive iron and a deeper slightly acidic zone (pH 5.5; zone III) with smaller amounts of iron. In this study, the impact of pH on the Fe(III)-reducing activities in both of these sediment zones was investigated, and molecular analyses that elucidated the sediment microbial diversity were performed. Fe(II) was formed in zone I and III sediment microcosms at rates that were approximately 710 and 895 nmol cm −3 day −1 , respectively. A shift to pH 5.3 conditions increased Fe(II) formation in zone I by a factor of 2. A shift to pH 3 conditions inhibited Fe(II) formation in zone III. Clone libraries revealed that the majority of the clones from both zones (approximately 44%) belonged to the Acidobacteria phylum. Since moderately acidophilic Acidobacteria species have the ability to oxidize Fe(II) and since Acidobacterium capsulatum reduced Fe oxides at pHs ranging from 2 to 5, this group appeared to be involved in the cycling of iron. PCR products specific for species related to Acidiphilium revealed that there were higher numbers of phylotypes related to cultured Acidiphilium or Acidisphaera species in zone III than in zone I. From the PCR products obtained for bioleaching-associated bacteria, only one phylotype with a level of similarity to Acidithiobacillus ferrooxidans of 99% was obtained. Using primer sets specific for Geobacteraceae , PCR products were obtained in higher DNA dilutions from zone III than from zone I. Phylogenetic analysis of clone libraries obtained from Fe(III)-reducing enrichment cultures grown at pH 5.5 revealed that the majority of clones were closely related to members of the Betaproteobacteria , primarily species of Thiomonas . Our results demonstrated that the upper acidic sediment was inhabited by acidophiles or moderate acidophiles which can also reduce Fe(III) under slightly acidic conditions. The majority of Fe(III) reducers inhabiting the slightly acidic sediment had only minor capacities to be active under acidic conditions. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Applied and Environmental Microbiology American Society For Microbiology

pH Gradient-Induced Heterogeneity of Fe(III)-Reducing Microorganisms in Coal Mining-Associated Lake Sediments

pH Gradient-Induced Heterogeneity of Fe(III)-Reducing Microorganisms in Coal Mining-Associated Lake Sediments

Applied and Environmental Microbiology , Volume 74 (4): 1019 – Feb 15, 2008

Abstract

pH Gradient-Induced Heterogeneity of Fe(III)-Reducing Microorganisms in Coal Mining-Associated Lake Sediments ▿ † Marco Blöthe 1 , ‡ , Denise M. Akob 2 , Joel E. Kostka 2 , Kathrin Göschel 1 , Harold L. Drake 1 and Kirsten Küsel 1 , 3 , * 1 Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany 2 Department of Oceanography, Florida State University, Tallahassee, Florida 32306 3 Limnology Research Group, Friedrich Schiller University Jena, 07743 Jena, Germany ABSTRACT Lakes formed because of coal mining are characterized by low pH and high concentrations of Fe(II) and sulfate. The anoxic sediment is often separated into an upper acidic zone (pH 3; zone I) with large amounts of reactive iron and a deeper slightly acidic zone (pH 5.5; zone III) with smaller amounts of iron. In this study, the impact of pH on the Fe(III)-reducing activities in both of these sediment zones was investigated, and molecular analyses that elucidated the sediment microbial diversity were performed. Fe(II) was formed in zone I and III sediment microcosms at rates that were approximately 710 and 895 nmol cm −3 day −1 , respectively. A shift to pH 5.3 conditions increased Fe(II) formation in zone I by a factor of 2. A shift to pH 3 conditions inhibited Fe(II) formation in zone III. Clone libraries revealed that the majority of the clones from both zones (approximately 44%) belonged to the Acidobacteria phylum. Since moderately acidophilic Acidobacteria species have the ability to oxidize Fe(II) and since Acidobacterium capsulatum reduced Fe oxides at pHs ranging from 2 to 5, this group appeared to be involved in the cycling of iron. PCR products specific for species related to Acidiphilium revealed that there were higher numbers of phylotypes related to cultured Acidiphilium or Acidisphaera species in zone III than in zone I. From the PCR products obtained for bioleaching-associated bacteria, only one phylotype with a level of similarity to Acidithiobacillus ferrooxidans of 99% was obtained. Using primer sets specific for Geobacteraceae , PCR products were obtained in higher DNA dilutions from zone III than from zone I. Phylogenetic analysis of clone libraries obtained from Fe(III)-reducing enrichment cultures grown at pH 5.5 revealed that the majority of clones were closely related to members of the Betaproteobacteria , primarily species of Thiomonas . Our results demonstrated that the upper acidic sediment was inhabited by acidophiles or moderate acidophiles which can also reduce Fe(III) under slightly acidic conditions. The majority of Fe(III) reducers inhabiting the slightly acidic sediment had only minor capacities to be active under acidic conditions.

Loading next page...
 
/lp/american-society-for-microbiology/ph-gradient-induced-heterogeneity-of-fe-iii-reducing-microorganisms-in-D2QnbcmFWn

References (81)

Publisher
American Society For Microbiology
Copyright
Copyright © 2008 by the American society for Microbiology.
ISSN
0099-2240
eISSN
1098-5336
DOI
10.1128/AEM.01194-07
pmid
18083864
Publisher site
See Article on Publisher Site

Abstract

pH Gradient-Induced Heterogeneity of Fe(III)-Reducing Microorganisms in Coal Mining-Associated Lake Sediments ▿ † Marco Blöthe 1 , ‡ , Denise M. Akob 2 , Joel E. Kostka 2 , Kathrin Göschel 1 , Harold L. Drake 1 and Kirsten Küsel 1 , 3 , * 1 Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany 2 Department of Oceanography, Florida State University, Tallahassee, Florida 32306 3 Limnology Research Group, Friedrich Schiller University Jena, 07743 Jena, Germany ABSTRACT Lakes formed because of coal mining are characterized by low pH and high concentrations of Fe(II) and sulfate. The anoxic sediment is often separated into an upper acidic zone (pH 3; zone I) with large amounts of reactive iron and a deeper slightly acidic zone (pH 5.5; zone III) with smaller amounts of iron. In this study, the impact of pH on the Fe(III)-reducing activities in both of these sediment zones was investigated, and molecular analyses that elucidated the sediment microbial diversity were performed. Fe(II) was formed in zone I and III sediment microcosms at rates that were approximately 710 and 895 nmol cm −3 day −1 , respectively. A shift to pH 5.3 conditions increased Fe(II) formation in zone I by a factor of 2. A shift to pH 3 conditions inhibited Fe(II) formation in zone III. Clone libraries revealed that the majority of the clones from both zones (approximately 44%) belonged to the Acidobacteria phylum. Since moderately acidophilic Acidobacteria species have the ability to oxidize Fe(II) and since Acidobacterium capsulatum reduced Fe oxides at pHs ranging from 2 to 5, this group appeared to be involved in the cycling of iron. PCR products specific for species related to Acidiphilium revealed that there were higher numbers of phylotypes related to cultured Acidiphilium or Acidisphaera species in zone III than in zone I. From the PCR products obtained for bioleaching-associated bacteria, only one phylotype with a level of similarity to Acidithiobacillus ferrooxidans of 99% was obtained. Using primer sets specific for Geobacteraceae , PCR products were obtained in higher DNA dilutions from zone III than from zone I. Phylogenetic analysis of clone libraries obtained from Fe(III)-reducing enrichment cultures grown at pH 5.5 revealed that the majority of clones were closely related to members of the Betaproteobacteria , primarily species of Thiomonas . Our results demonstrated that the upper acidic sediment was inhabited by acidophiles or moderate acidophiles which can also reduce Fe(III) under slightly acidic conditions. The majority of Fe(III) reducers inhabiting the slightly acidic sediment had only minor capacities to be active under acidic conditions.

Journal

Applied and Environmental MicrobiologyAmerican Society For Microbiology

Published: Feb 15, 2008

There are no references for this article.