The Experts below are selected from a list of 153 Experts worldwide ranked by ideXlab platform
Michael Schlömann - One of the best experts on this subject based on the ideXlab platform.
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Iron targeted transcriptome study draws attention to novel redox protein candidates involved in ferrous Iron oxidation in "Ferrovum" sp. JA12.
Research in microbiology, 2018Co-Authors: Sophie R. Ullrich, Anja Poehlein, Martin Mühling, Gloria Levicán, Michael SchlömannAbstract:Abstract The response of the acidophilic Iron Oxidizer “Ferrovum” sp. JA12 to elevated concentrations of ferrous Iron was targeted at transcriptome level in order to assess models on oxidative stress management and ferrous Iron oxidation. Overall transcriptome profiles indicate a high cellular activity of “Ferrovum” sp. JA12 up to 50 mM of ferrous Iron with genes predicted to be involved in Iron oxidation, carbon fixation and ribosome formation showing the highest transcript levels. The data support the Iron oxidation pathway inferred from genome analysis and draws attention to further redox proteins potentially associated with Iron oxidation. The restriction of homologous proteins to Iron oxidizing beta- and zetaproteobacteria underlines the previous notion of a common origin of Iron oxidation in these phyla. Detoxification of reactive oxygen species and primary products of oxidative damage of membrane lipids appears to be of permanent relevance under conditions mimicking those of the original habitat of “Ferrovum” sp. JA12. Also the maintenance of a reverse membrane potential appears to be its most important strategy to withstand the acidic external pH.
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Molecular Response of the Acidophilic Iron Oxidizer “ Ferrovum ” sp. JA12 to the Exposure to Elevated Concentrations of Ferrous Iron
Solid State Phenomena, 2017Co-Authors: Sophie R. Ullrich, Michael Schlömann, Anja Poehlein, Gloria Levicán, Martin MühlingAbstract:The response to elevated ferrous Iron concentrations was investigated in the acidophilic Iron Oxidizer “Ferrovum” sp. JA12 at transcriptome level. Detoxification of reactive oxygen species appears to be the most important strategy to cope with oxidative stress. The proposed Iron oxidation model in “Ferrovum” spp. was supported by the transcriptome data of “Ferrovum” sp. JA12. Several gene candidates of the Iron oxidation model are organized in a gene cluster conserved in Iron oxidizing betaproteobacteria and zetaproteobacteria possibly indicating a common origin of Iron oxidation.
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A thermophilic-like ene-reductase originating from an acidophilic Iron Oxidizer
Applied Microbiology and Biotechnology, 2017Co-Authors: Anika Scholtissek, Michael Schlömann, Martin Mühling, Sophie R. Ullrich, Caroline E. Paul, Dirk TischlerAbstract:Ene-reductases originating from extremophiles are gaining importance in the field of biocatalysis due to higher-stability properties. The genome of the acidophilic Iron-oxidizing bacterium “ Ferrovum” sp. JA12 was found to harbor a thermophilic-like ene-reductase ( F OYE-1). The foye-1 gene was ligated into a pET16bp expression vector system, and the enzyme was produced in Escherichia coli BL21 (DE3; pLysS) cells in yields of 10 mg L^−1. F OYE-1 showed remarkable activity and rates on N -phenylmaleimide and N -phenyl- 2 -methylmaleimide (up to 89 U mg^−1, >97 % conversion, 95 % ( R )-selective) with both nicotinamide cofactors, NADPH and NADH. The catalytic efficiency with NADPH was 27 times higher compared to NADH. At the temperature maximum (50 °C) and pH optimum (6.5), activity was almost doubled to 160 U mg^−1. These findings accomplish F OYE-1 for a valuable biocatalyst in the synthesis of succinimides. The appearance of a thermophilic-like ene-reductase in an acidic habitat is discussed with respect to its phylogenetic placement and to the genomic neighborhood of the encoding gene, awarding F OYE-1 a putative involvement in a quorum-sensing process.
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Reconstruction of the Metabolic Potential of Acidophilic Sideroxydans Strains from the Metagenome of an Microaerophilic Enrichment Culture of Acidophilic Iron-Oxidizing Bacteria from a Pilot Plant for the Treatment of Acid Mine Drainage Reveals Metab
Frontiers in microbiology, 2016Co-Authors: Martin Mühling, Anja Poehlein, Anna Stuhr, Matthias Voitel, Rolf Daniel, Michael SchlömannAbstract:Bacterial community analyses of samples from a pilot plant for the treatment of acid mine drainage (AMD) from the lignite-mining district in Lusatia (East Germany) had previously demonstrated the dominance of two groups of acidophilic Iron Oxidizers: the novel candidate genus "Ferrovum" and a group comprising Gallionella-like strains. Since pure culture had proven difficult, previous studies have used genome analyses of co-cultures consisting of “Ferrovum” and a strain of the heterotrophic acidophile Acidiphilium in order to obtain insight into the life style of these novel bacteria. Here we report on attempts to undertake a similar study on Gallionella-like acidophiles from AMD. Isolates belonging to the family Gallionellaceae are still restricted to the microaerophilic and neutrophilic Iron Oxidizers Sideroxydans and Gallionella. Availability of genomic or metagenomic sequence data of acidophilic strains of these genera should, therefore, be relevant for defining adaptive strategies in pH homeostasis. This is particularly the case since complete genome sequences of the neutrophilic strains G. capsiferriformans ES-2 and S. lithotrophicus ES-1 permit the direct comparison of the metabolic capacity of neutrophilic and acidophilic members of the same genus and, thus, the detection of biochemical features that are specific to acidophilic strains to support life under acidic conditions. Isolation attempts undertaken in this study resulted in the microaerophilic enrichment culture ADE-12-1 which, based on 16S rRNA gene sequence analysis, consisted of at least three to four distinct Gallionellaceae strains that appear to be closely related to the neutrophilic Iron Oxidizer S. lithotrophicus ES-1. Key hypotheses inferred from the metabolic reconstruction of the metagenomic sequence data of these acidophilic Sideroxydans strains include the putative role of urea hydrolysis, formate oxidation and cyanophycin decarboxylation in pH homeostasis.
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Genome Sequence of the Acidophilic Iron Oxidizer Ferrimicrobium acidiphilum Strain T23T
Genome announcements, 2015Co-Authors: Sebastian Eisen, D. Barrie Johnson, Michael Schlömann, Anja Poehlein, Rolf Daniel, Martin MühlingAbstract:ABSTRACT Extremely acidophilic Iron-oxidizing bacteria have largely been characterized for the phyla Proteobacteria and Nitrospira. Here, we report the draft genome of an Iron-oxidizing and -reducing heterotrophic mesophile of the Actinobacteria, Ferrimicrobium acidiphilum, which was isolated from an abandoned pyrite mine. The genome sequence comprises 3.08 Mb.
Jianqun Lin - One of the best experts on this subject based on the ideXlab platform.
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The substrate-dependent regulatory effects of the AfeI/R system in Acidithiobacillus ferrooxidans reveals the novel regulation strategy of quorum sensing in acidophiles.
Environmental Microbiology, 2020Co-Authors: Xue-yan Gao, Likai Hao, Rui Wang, Jianqiang Lin, Xiangmei Liu, Xin Pang, Chengjia Zhang, Jianqun LinAbstract:A LuxI/R-like quorum sensing (QS) system (AfeI/R) has been reported in the acidophilic and chemoautotrophic Acidithiobacillus spp. However, the function of AfeI/R remains unclear because of the difficulties in the genetic manipulation of these bacteria. Here, we constructed different afeI mutants of the sulfur- and Iron-Oxidizer A. ferrooxidans, identified the N-acyl homoserine lactones (acyl-HSLs) synthesized by AfeI, and determined the regulatory effects of AfeI/R on genes expression, extracellular polymeric substance synthesis, energy metabolism, cell growth and population density of A. ferrooxidans in different energy substrates. Acyl-HSLs-mediated distinct regulation strategies were employed to influence bacterial metabolism and cell growth of A. ferrooxidans cultivated in either sulfur or ferrous Iron. Based on these findings, an energy-substrate-dependent regulation mode of AfeI/R in A. ferrooxidans was illuminated that AfeI/R could produce different types of acyl-HSLs and employ specific acyl-HSLs to regulate specific genes in response to different energy substrates. The discovery of the AfeI/R-mediated substrate-dependent regulatory mode expands our knowledge on the function of QS system in the chemoautotrophic sulfur- and ferrous Iron-oxidizing bacteria, and provides new insights in understanding energy metabolism modulation, population control, bacteria-driven bioleaching process, and the coevolution between the acidophiles and their acidic habitats.
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the substrate dependent regulatory effects of the afei r system in acidithiobacillus ferrooxidans reveals the novel regulation strategy of quorum sensing in acidophiles
Environmental Microbiology, 2020Co-Authors: Xue-yan Gao, Likai Hao, Rui Wang, Jianqiang Lin, Xiangmei Liu, Xin Pang, Chengjia Zhang, Jianqun Lin, Linxu ChenAbstract:A LuxI/R-like quorum sensing (QS) system (AfeI/R) has been reported in the acidophilic and chemoautotrophic Acidithiobacillus spp. However, the function of AfeI/R remains unclear because of the difficulties in the genetic manipulation of these bacteria. Here, we constructed different afeI mutants of the sulfur- and Iron-Oxidizer A. ferrooxidans, identified the N-acyl homoserine lactones (acyl-HSLs) synthesized by AfeI, and determined the regulatory effects of AfeI/R on genes expression, extracellular polymeric substance synthesis, energy metabolism, cell growth and population density of A. ferrooxidans in different energy substrates. Acyl-HSLs-mediated distinct regulation strategies were employed to influence bacterial metabolism and cell growth of A. ferrooxidans cultivated in either sulfur or ferrous Iron. Based on these findings, an energy-substrate-dependent regulation mode of AfeI/R in A. ferrooxidans was illuminated that AfeI/R could produce different types of acyl-HSLs and employ specific acyl-HSLs to regulate specific genes in response to different energy substrates. The discovery of the AfeI/R-mediated substrate-dependent regulatory mode expands our knowledge on the function of QS system in the chemoautotrophic sulfur- and ferrous Iron-oxidizing bacteria, and provides new insights in understanding energy metabolism modulation, population control, bacteria-driven bioleaching process, and the coevolution between the acidophiles and their acidic habitats.
Likai Hao - One of the best experts on this subject based on the ideXlab platform.
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The substrate-dependent regulatory effects of the AfeI/R system in Acidithiobacillus ferrooxidans reveals the novel regulation strategy of quorum sensing in acidophiles.
Environmental Microbiology, 2020Co-Authors: Xue-yan Gao, Likai Hao, Rui Wang, Jianqiang Lin, Xiangmei Liu, Xin Pang, Chengjia Zhang, Jianqun LinAbstract:A LuxI/R-like quorum sensing (QS) system (AfeI/R) has been reported in the acidophilic and chemoautotrophic Acidithiobacillus spp. However, the function of AfeI/R remains unclear because of the difficulties in the genetic manipulation of these bacteria. Here, we constructed different afeI mutants of the sulfur- and Iron-Oxidizer A. ferrooxidans, identified the N-acyl homoserine lactones (acyl-HSLs) synthesized by AfeI, and determined the regulatory effects of AfeI/R on genes expression, extracellular polymeric substance synthesis, energy metabolism, cell growth and population density of A. ferrooxidans in different energy substrates. Acyl-HSLs-mediated distinct regulation strategies were employed to influence bacterial metabolism and cell growth of A. ferrooxidans cultivated in either sulfur or ferrous Iron. Based on these findings, an energy-substrate-dependent regulation mode of AfeI/R in A. ferrooxidans was illuminated that AfeI/R could produce different types of acyl-HSLs and employ specific acyl-HSLs to regulate specific genes in response to different energy substrates. The discovery of the AfeI/R-mediated substrate-dependent regulatory mode expands our knowledge on the function of QS system in the chemoautotrophic sulfur- and ferrous Iron-oxidizing bacteria, and provides new insights in understanding energy metabolism modulation, population control, bacteria-driven bioleaching process, and the coevolution between the acidophiles and their acidic habitats.
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the substrate dependent regulatory effects of the afei r system in acidithiobacillus ferrooxidans reveals the novel regulation strategy of quorum sensing in acidophiles
Environmental Microbiology, 2020Co-Authors: Xue-yan Gao, Likai Hao, Rui Wang, Jianqiang Lin, Xiangmei Liu, Xin Pang, Chengjia Zhang, Jianqun Lin, Linxu ChenAbstract:A LuxI/R-like quorum sensing (QS) system (AfeI/R) has been reported in the acidophilic and chemoautotrophic Acidithiobacillus spp. However, the function of AfeI/R remains unclear because of the difficulties in the genetic manipulation of these bacteria. Here, we constructed different afeI mutants of the sulfur- and Iron-Oxidizer A. ferrooxidans, identified the N-acyl homoserine lactones (acyl-HSLs) synthesized by AfeI, and determined the regulatory effects of AfeI/R on genes expression, extracellular polymeric substance synthesis, energy metabolism, cell growth and population density of A. ferrooxidans in different energy substrates. Acyl-HSLs-mediated distinct regulation strategies were employed to influence bacterial metabolism and cell growth of A. ferrooxidans cultivated in either sulfur or ferrous Iron. Based on these findings, an energy-substrate-dependent regulation mode of AfeI/R in A. ferrooxidans was illuminated that AfeI/R could produce different types of acyl-HSLs and employ specific acyl-HSLs to regulate specific genes in response to different energy substrates. The discovery of the AfeI/R-mediated substrate-dependent regulatory mode expands our knowledge on the function of QS system in the chemoautotrophic sulfur- and ferrous Iron-oxidizing bacteria, and provides new insights in understanding energy metabolism modulation, population control, bacteria-driven bioleaching process, and the coevolution between the acidophiles and their acidic habitats.
Xue-yan Gao - One of the best experts on this subject based on the ideXlab platform.
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The substrate-dependent regulatory effects of the AfeI/R system in Acidithiobacillus ferrooxidans reveals the novel regulation strategy of quorum sensing in acidophiles.
Environmental Microbiology, 2020Co-Authors: Xue-yan Gao, Likai Hao, Rui Wang, Jianqiang Lin, Xiangmei Liu, Xin Pang, Chengjia Zhang, Jianqun LinAbstract:A LuxI/R-like quorum sensing (QS) system (AfeI/R) has been reported in the acidophilic and chemoautotrophic Acidithiobacillus spp. However, the function of AfeI/R remains unclear because of the difficulties in the genetic manipulation of these bacteria. Here, we constructed different afeI mutants of the sulfur- and Iron-Oxidizer A. ferrooxidans, identified the N-acyl homoserine lactones (acyl-HSLs) synthesized by AfeI, and determined the regulatory effects of AfeI/R on genes expression, extracellular polymeric substance synthesis, energy metabolism, cell growth and population density of A. ferrooxidans in different energy substrates. Acyl-HSLs-mediated distinct regulation strategies were employed to influence bacterial metabolism and cell growth of A. ferrooxidans cultivated in either sulfur or ferrous Iron. Based on these findings, an energy-substrate-dependent regulation mode of AfeI/R in A. ferrooxidans was illuminated that AfeI/R could produce different types of acyl-HSLs and employ specific acyl-HSLs to regulate specific genes in response to different energy substrates. The discovery of the AfeI/R-mediated substrate-dependent regulatory mode expands our knowledge on the function of QS system in the chemoautotrophic sulfur- and ferrous Iron-oxidizing bacteria, and provides new insights in understanding energy metabolism modulation, population control, bacteria-driven bioleaching process, and the coevolution between the acidophiles and their acidic habitats.
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the substrate dependent regulatory effects of the afei r system in acidithiobacillus ferrooxidans reveals the novel regulation strategy of quorum sensing in acidophiles
Environmental Microbiology, 2020Co-Authors: Xue-yan Gao, Likai Hao, Rui Wang, Jianqiang Lin, Xiangmei Liu, Xin Pang, Chengjia Zhang, Jianqun Lin, Linxu ChenAbstract:A LuxI/R-like quorum sensing (QS) system (AfeI/R) has been reported in the acidophilic and chemoautotrophic Acidithiobacillus spp. However, the function of AfeI/R remains unclear because of the difficulties in the genetic manipulation of these bacteria. Here, we constructed different afeI mutants of the sulfur- and Iron-Oxidizer A. ferrooxidans, identified the N-acyl homoserine lactones (acyl-HSLs) synthesized by AfeI, and determined the regulatory effects of AfeI/R on genes expression, extracellular polymeric substance synthesis, energy metabolism, cell growth and population density of A. ferrooxidans in different energy substrates. Acyl-HSLs-mediated distinct regulation strategies were employed to influence bacterial metabolism and cell growth of A. ferrooxidans cultivated in either sulfur or ferrous Iron. Based on these findings, an energy-substrate-dependent regulation mode of AfeI/R in A. ferrooxidans was illuminated that AfeI/R could produce different types of acyl-HSLs and employ specific acyl-HSLs to regulate specific genes in response to different energy substrates. The discovery of the AfeI/R-mediated substrate-dependent regulatory mode expands our knowledge on the function of QS system in the chemoautotrophic sulfur- and ferrous Iron-oxidizing bacteria, and provides new insights in understanding energy metabolism modulation, population control, bacteria-driven bioleaching process, and the coevolution between the acidophiles and their acidic habitats.
Martin Mühling - One of the best experts on this subject based on the ideXlab platform.
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Iron targeted transcriptome study draws attention to novel redox protein candidates involved in ferrous Iron oxidation in "Ferrovum" sp. JA12.
Research in microbiology, 2018Co-Authors: Sophie R. Ullrich, Anja Poehlein, Martin Mühling, Gloria Levicán, Michael SchlömannAbstract:Abstract The response of the acidophilic Iron Oxidizer “Ferrovum” sp. JA12 to elevated concentrations of ferrous Iron was targeted at transcriptome level in order to assess models on oxidative stress management and ferrous Iron oxidation. Overall transcriptome profiles indicate a high cellular activity of “Ferrovum” sp. JA12 up to 50 mM of ferrous Iron with genes predicted to be involved in Iron oxidation, carbon fixation and ribosome formation showing the highest transcript levels. The data support the Iron oxidation pathway inferred from genome analysis and draws attention to further redox proteins potentially associated with Iron oxidation. The restriction of homologous proteins to Iron oxidizing beta- and zetaproteobacteria underlines the previous notion of a common origin of Iron oxidation in these phyla. Detoxification of reactive oxygen species and primary products of oxidative damage of membrane lipids appears to be of permanent relevance under conditions mimicking those of the original habitat of “Ferrovum” sp. JA12. Also the maintenance of a reverse membrane potential appears to be its most important strategy to withstand the acidic external pH.
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Molecular Response of the Acidophilic Iron Oxidizer “ Ferrovum ” sp. JA12 to the Exposure to Elevated Concentrations of Ferrous Iron
Solid State Phenomena, 2017Co-Authors: Sophie R. Ullrich, Michael Schlömann, Anja Poehlein, Gloria Levicán, Martin MühlingAbstract:The response to elevated ferrous Iron concentrations was investigated in the acidophilic Iron Oxidizer “Ferrovum” sp. JA12 at transcriptome level. Detoxification of reactive oxygen species appears to be the most important strategy to cope with oxidative stress. The proposed Iron oxidation model in “Ferrovum” spp. was supported by the transcriptome data of “Ferrovum” sp. JA12. Several gene candidates of the Iron oxidation model are organized in a gene cluster conserved in Iron oxidizing betaproteobacteria and zetaproteobacteria possibly indicating a common origin of Iron oxidation.
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A thermophilic-like ene-reductase originating from an acidophilic Iron Oxidizer
Applied Microbiology and Biotechnology, 2017Co-Authors: Anika Scholtissek, Michael Schlömann, Martin Mühling, Sophie R. Ullrich, Caroline E. Paul, Dirk TischlerAbstract:Ene-reductases originating from extremophiles are gaining importance in the field of biocatalysis due to higher-stability properties. The genome of the acidophilic Iron-oxidizing bacterium “ Ferrovum” sp. JA12 was found to harbor a thermophilic-like ene-reductase ( F OYE-1). The foye-1 gene was ligated into a pET16bp expression vector system, and the enzyme was produced in Escherichia coli BL21 (DE3; pLysS) cells in yields of 10 mg L^−1. F OYE-1 showed remarkable activity and rates on N -phenylmaleimide and N -phenyl- 2 -methylmaleimide (up to 89 U mg^−1, >97 % conversion, 95 % ( R )-selective) with both nicotinamide cofactors, NADPH and NADH. The catalytic efficiency with NADPH was 27 times higher compared to NADH. At the temperature maximum (50 °C) and pH optimum (6.5), activity was almost doubled to 160 U mg^−1. These findings accomplish F OYE-1 for a valuable biocatalyst in the synthesis of succinimides. The appearance of a thermophilic-like ene-reductase in an acidic habitat is discussed with respect to its phylogenetic placement and to the genomic neighborhood of the encoding gene, awarding F OYE-1 a putative involvement in a quorum-sensing process.
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Reconstruction of the Metabolic Potential of Acidophilic Sideroxydans Strains from the Metagenome of an Microaerophilic Enrichment Culture of Acidophilic Iron-Oxidizing Bacteria from a Pilot Plant for the Treatment of Acid Mine Drainage Reveals Metab
Frontiers in microbiology, 2016Co-Authors: Martin Mühling, Anja Poehlein, Anna Stuhr, Matthias Voitel, Rolf Daniel, Michael SchlömannAbstract:Bacterial community analyses of samples from a pilot plant for the treatment of acid mine drainage (AMD) from the lignite-mining district in Lusatia (East Germany) had previously demonstrated the dominance of two groups of acidophilic Iron Oxidizers: the novel candidate genus "Ferrovum" and a group comprising Gallionella-like strains. Since pure culture had proven difficult, previous studies have used genome analyses of co-cultures consisting of “Ferrovum” and a strain of the heterotrophic acidophile Acidiphilium in order to obtain insight into the life style of these novel bacteria. Here we report on attempts to undertake a similar study on Gallionella-like acidophiles from AMD. Isolates belonging to the family Gallionellaceae are still restricted to the microaerophilic and neutrophilic Iron Oxidizers Sideroxydans and Gallionella. Availability of genomic or metagenomic sequence data of acidophilic strains of these genera should, therefore, be relevant for defining adaptive strategies in pH homeostasis. This is particularly the case since complete genome sequences of the neutrophilic strains G. capsiferriformans ES-2 and S. lithotrophicus ES-1 permit the direct comparison of the metabolic capacity of neutrophilic and acidophilic members of the same genus and, thus, the detection of biochemical features that are specific to acidophilic strains to support life under acidic conditions. Isolation attempts undertaken in this study resulted in the microaerophilic enrichment culture ADE-12-1 which, based on 16S rRNA gene sequence analysis, consisted of at least three to four distinct Gallionellaceae strains that appear to be closely related to the neutrophilic Iron Oxidizer S. lithotrophicus ES-1. Key hypotheses inferred from the metabolic reconstruction of the metagenomic sequence data of these acidophilic Sideroxydans strains include the putative role of urea hydrolysis, formate oxidation and cyanophycin decarboxylation in pH homeostasis.
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Genome Sequence of the Acidophilic Iron Oxidizer Ferrimicrobium acidiphilum Strain T23T
Genome announcements, 2015Co-Authors: Sebastian Eisen, D. Barrie Johnson, Michael Schlömann, Anja Poehlein, Rolf Daniel, Martin MühlingAbstract:ABSTRACT Extremely acidophilic Iron-oxidizing bacteria have largely been characterized for the phyla Proteobacteria and Nitrospira. Here, we report the draft genome of an Iron-oxidizing and -reducing heterotrophic mesophile of the Actinobacteria, Ferrimicrobium acidiphilum, which was isolated from an abandoned pyrite mine. The genome sequence comprises 3.08 Mb.
