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Kenneth H Nealson - One of the best experts on this subject based on the ideXlab platform.
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purification and properties of a low redox potential tetraheme cytochrome c3 from Shewanella putrefaciens
Journal of Bacteriology, 1996Co-Authors: A I Tsapin, Kenneth H Nealson, T Meyers, M A Cusanovich, J Van Beuumen, L D Crosby, B A Feinberg, C ZhangAbstract:Shewanella putrefaciens is a facultatively anaerobic bacterium in the gamma group of the proteobacteria, capable of utilizing a wide variety of anaerobic electron acceptors. An examination of its cytochrome content revealed the presence of a tetraheme, low-redox-potential (E'o = -233 mV), cytochrome c-type cytochrome with a molecular mass of 12,120 Da and a pI of 5.8. The electron spin resonance data indicate a bis-histidine coordination of heme groups. Reduction of ferric citrate was accompanied by oxidation of the cytochrome. The biochemical properties suggested that this protein was in the cytochrome c3 group, which is supported by N-terminal sequence data up to the first heme binding site.
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Structure and properties of novel inclusions in Shewanella putrefaciens
FEMS microbiology letters, 1996Co-Authors: Birgit Krause, Terry J. Beveridge, Charles C. Remsen, Kenneth H NealsonAbstract:Cytoplasmic inclusions surrounded by a bilayer membrane were seen in thin sections, negatively stained and freeze-fractured preparations of Shewanella putrefaciens. Cells harvested from the late exponential and early stationary phase showed a higher number of these vesicles than bacteria isolated from early exponential or late stationary phase. Chemical dyes for polyphosphate or poly-β-hydroxybutyrate did not stain the material enclosed within these vesicles. Elemental analysis of the material indicated that the content was organic in nature and might be a protein. HPLC analysis of the material showed that it was probably not a carbon source, nor an electron acceptor used by S. putrefaciens.
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Transformation of tetrachloromethane by Shewanella putrefaciens MR-1
1995Co-Authors: Erik Petrovskis, Peter Adriaens, T.m. Vogel, D.a. Saffarini, Kenneth H NealsonAbstract:The dissimilatory metal-reducing facultative anaerobe Shewanella putrefaciens MR-1 has been shown to transform chlorinated methanes by biotic and abiotic processes under Fe(III)-respiring conditions. MR-1 produces magnetite and other Fe(II)-containing compounds that dehalogenate tetrachloromethane (CT) and trichloromethane (CF) abiotically. The biological CT transformation activity has been localized utilizing metabolic inhibitors and respiratory mutants. Cytochrome and iron-sulfur complex inhibitors did not block CT transformation. Terminal reductase mutants showed wild-type CT transformation activity. However, menaquinone-deficient mutants lost 90% of the CT transformation activity. This represents the first direct evidence of respiratory chain involvement in reductive dehalogenation.
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anaerobic electron acceptor chemotaxis in Shewanella putrefaciens
Applied and Environmental Microbiology, 1995Co-Authors: Kenneth H Nealson, Duane P Moser, Daad A. SaffariniAbstract:Shewanella putrefaciens MR-1 can grow either aerobically or anaerobically at the expense of many different electron acceptors and is often found in abundance at redox interfaces in nature. Such redox interfaces are often characterized by very strong gradients of electron acceptors resulting from rapid microbial metabolism. The coincidence of S. putrefaciens abundance with environmental gradients prompted an examination of the ability of MR-1 to sense and respond to electron acceptor gradients in the laboratory. In these experiments, taxis to the majority of the electron acceptors that S. putrefaciens utilizes for anaerobic growth was seen. All anaerobic electron acceptor taxis was eliminated by the presence of oxygen, nitrate, nitrite, elemental sulfur, or dimethyl sulfoxide, even though taxis to the latter was very weak and nitrate and nitrite respiration was normal in the presence of dimethyl sulfoxide. Studies with respiratory mutants of MR-1 revealed that several electron acceptors that could not be used for anaerobic growth nevertheless elicited normal anaerobic taxis. Mutant M56, which was unable to respire nitrite, showed normal taxis to nitrite, as well as the inhibition of taxis to other electron acceptors by nitrite. These results indicate that electron acceptor taxis in S. putrefaciens does not conform to the paradigm established for Escherichia coli and several other bacteria. Carbon chemo-taxis was also unusual in this organism: of all carbon compounds tested, the only positive response observed was to formate under anaerobic conditions.
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A biochemical study of the intermediary carbon metabolism of Shewanella putrefaciens.
Journal of bacteriology, 1994Co-Authors: J.h. Scott, Kenneth H NealsonAbstract:Cell extracts were used to determine the enzymes involved in the intermediary carbon metabolism of several strains of Shewanella putrefaciens. Enzymes of the Entner-Doudoroff pathway (6-phosphogluconate dehydratase and 2-keto-3-deoxy-6-phosphogluconate aldolase) were detected, but those of the Embden-Meyerhof-Parnas pathway were not. While several tricarboxylic acid cycle enzymes were present under both aerobic and anaerobic conditions, two key enzymes (2-oxoglutarate dehydrogenase and pyruvate dehydrogenase) were greatly diminished under anaerobic conditions. Extracts of cell grown anaerobically on formate as the sole source of carbon and energy were positive for hydroxypyruvate reductase, the key enzyme of the serine pathway in other methylotrophs, while no hexulose synthase activity was seen.
Jizhong Zhou - One of the best experts on this subject based on the ideXlab platform.
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Roles of UndA and MtrC of Shewanella putrefaciens W3-18-1 in iron reduction
BMC microbiology, 2013Co-Authors: Yunfeng Yang, Dongru Qiu, Jingrong Chen, Jizhong ZhouAbstract:Background: The completion of genome sequencing in a number of Shewanella species, which are most renowned for their metal reduction capacity, offers a basis for comparative studies. Previous work in Shewanella oneidensis MR-1 has indicated that some genes within a cluster (mtrBAC-omcA-mtrFED) were involved in iron reduction. To explore new features of iron reduction pathways, we experimentally analyzed Shewanella putrefaciens W3-18-1 since its gene cluster is considerably different from that of MR-1 in that the gene cluster encodes only four ORFs. Results: Among the gene cluster, two genes (mtrC and undA) were shown to encode c-type cytochromes. The Delta mtrC deletion mutant revealed significant deficiencies in reducing metals of Fe2O3, a-FeO(OH), beta-FeO(OH), ferric citrate, Mn (IV) and Co(III), but not organic compounds. In contrast, no deficiency of metal reduction was observed in the Delta undA deletion mutant. Nonetheless, undA deletion resulted in progressively slower iron reduction in the absence of mtrC and fitness loss under the iron-using condition, which was indicative of a functional role of UndA in iron reduction. Conclusions: These results provide physiological and biochemical evidences that UndA and MtrC of Shewanella putrefaciens W3-18-1 are involved in iron reduction.
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Combined genomics and experimental analyses of respiratory characteristics of Shewanella putrefaciens W3-18-1.
Applied and environmental microbiology, 2013Co-Authors: Dongru Qiu, Hehong Wei, Yunfeng Yang, Ming Xie, Jingrong Chen, Mark H. Pinkerton, Yili Liang, Jizhong ZhouAbstract:It has previously been shown that the Shewanella putrefaciens W3-18-1 strain produces remarkably high current in microbial fuel cells (MFCs) and can form magnetite at 0 degrees C. To explore the underlying mechanisms, we developed a genetic manipulation method by deleting the restriction-modification system genes of the SGI1 (Salmonella genome island 1)-like prophage and analyzed the key genes involved in bacterial respiration. W3-18-1 has less respiratory flexibility than the well-characterized S. oneidensis MR-1 strain, as it possesses fewer cytochrome c genes and lacks the ability to oxidize sulfite or reduce dimethyl sulfoxide (DMSO) and timethylamine oxide (TMAO). W3-18-1 lacks the hydrogen-producing Fe-only hydrogenase, and the hydrogen-oxidizing Ni-Fe hydrogenase genes were split into two separate clusters. Two periplasmic nitrate reductases (NapDAGHB and NapDABC) were functionally redundant in anaerobic growth of W3-18-1 with nitrate as the electron acceptor, though napDABC was not regulated by Crp. Moreover, nitrate respiration started earlier in W3-18-1 than in MR-1 (with NapDAGHB only) under microoxic conditions. These results indicate that Shewanella putrefaciens W3-18-1 is well adapted to habitats with higher oxygen levels. Taken together, the results of this study provide valuable insights into bacterial genome evolution.
Michael W. Kessler - One of the best experts on this subject based on the ideXlab platform.
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Palmar Soft Tissue Infection From Shewanella putrefaciens.
The Journal of hand surgery, 2017Co-Authors: James M. Ryan, Elizabeth C. Truelove, Matthew Sabatino, Stephen P. Peters, Michael W. KesslerAbstract:Shewanella putrefaciens, a gram-negative bacillus, ubiquitous in marine environments, is an opportunistic agent reported to cause rare human infection, most commonly in patients who are immunocompromised or who have a preexisting soft tissue defect. We present an immunocompetent, 40-year-old woman with a soft tissue infection of the left palm caused by S. putrefaciens. The patient's infection was complicated by the presence of retained foreign bodies, seashell fragments, from a traumatic fall. Following appropriate evaluation and surgical treatment, our patient experienced a successful outcome with no recurrence of infection or deficit in the affected hand. This case report complements the growing literature regarding morbidity attributed to S. putrefaciens infection.
Dongru Qiu - One of the best experts on this subject based on the ideXlab platform.
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Roles of UndA and MtrC of Shewanella putrefaciens W3-18-1 in iron reduction
BMC microbiology, 2013Co-Authors: Yunfeng Yang, Dongru Qiu, Jingrong Chen, Jizhong ZhouAbstract:Background: The completion of genome sequencing in a number of Shewanella species, which are most renowned for their metal reduction capacity, offers a basis for comparative studies. Previous work in Shewanella oneidensis MR-1 has indicated that some genes within a cluster (mtrBAC-omcA-mtrFED) were involved in iron reduction. To explore new features of iron reduction pathways, we experimentally analyzed Shewanella putrefaciens W3-18-1 since its gene cluster is considerably different from that of MR-1 in that the gene cluster encodes only four ORFs. Results: Among the gene cluster, two genes (mtrC and undA) were shown to encode c-type cytochromes. The Delta mtrC deletion mutant revealed significant deficiencies in reducing metals of Fe2O3, a-FeO(OH), beta-FeO(OH), ferric citrate, Mn (IV) and Co(III), but not organic compounds. In contrast, no deficiency of metal reduction was observed in the Delta undA deletion mutant. Nonetheless, undA deletion resulted in progressively slower iron reduction in the absence of mtrC and fitness loss under the iron-using condition, which was indicative of a functional role of UndA in iron reduction. Conclusions: These results provide physiological and biochemical evidences that UndA and MtrC of Shewanella putrefaciens W3-18-1 are involved in iron reduction.
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Combined genomics and experimental analyses of respiratory characteristics of Shewanella putrefaciens W3-18-1.
Applied and environmental microbiology, 2013Co-Authors: Dongru Qiu, Hehong Wei, Yunfeng Yang, Ming Xie, Jingrong Chen, Mark H. Pinkerton, Yili Liang, Jizhong ZhouAbstract:It has previously been shown that the Shewanella putrefaciens W3-18-1 strain produces remarkably high current in microbial fuel cells (MFCs) and can form magnetite at 0 degrees C. To explore the underlying mechanisms, we developed a genetic manipulation method by deleting the restriction-modification system genes of the SGI1 (Salmonella genome island 1)-like prophage and analyzed the key genes involved in bacterial respiration. W3-18-1 has less respiratory flexibility than the well-characterized S. oneidensis MR-1 strain, as it possesses fewer cytochrome c genes and lacks the ability to oxidize sulfite or reduce dimethyl sulfoxide (DMSO) and timethylamine oxide (TMAO). W3-18-1 lacks the hydrogen-producing Fe-only hydrogenase, and the hydrogen-oxidizing Ni-Fe hydrogenase genes were split into two separate clusters. Two periplasmic nitrate reductases (NapDAGHB and NapDABC) were functionally redundant in anaerobic growth of W3-18-1 with nitrate as the electron acceptor, though napDABC was not regulated by Crp. Moreover, nitrate respiration started earlier in W3-18-1 than in MR-1 (with NapDAGHB only) under microoxic conditions. These results indicate that Shewanella putrefaciens W3-18-1 is well adapted to habitats with higher oxygen levels. Taken together, the results of this study provide valuable insights into bacterial genome evolution.
Yunfeng Yang - One of the best experts on this subject based on the ideXlab platform.
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Roles of UndA and MtrC of Shewanella putrefaciens W3-18-1 in iron reduction
BMC microbiology, 2013Co-Authors: Yunfeng Yang, Dongru Qiu, Jingrong Chen, Jizhong ZhouAbstract:Background: The completion of genome sequencing in a number of Shewanella species, which are most renowned for their metal reduction capacity, offers a basis for comparative studies. Previous work in Shewanella oneidensis MR-1 has indicated that some genes within a cluster (mtrBAC-omcA-mtrFED) were involved in iron reduction. To explore new features of iron reduction pathways, we experimentally analyzed Shewanella putrefaciens W3-18-1 since its gene cluster is considerably different from that of MR-1 in that the gene cluster encodes only four ORFs. Results: Among the gene cluster, two genes (mtrC and undA) were shown to encode c-type cytochromes. The Delta mtrC deletion mutant revealed significant deficiencies in reducing metals of Fe2O3, a-FeO(OH), beta-FeO(OH), ferric citrate, Mn (IV) and Co(III), but not organic compounds. In contrast, no deficiency of metal reduction was observed in the Delta undA deletion mutant. Nonetheless, undA deletion resulted in progressively slower iron reduction in the absence of mtrC and fitness loss under the iron-using condition, which was indicative of a functional role of UndA in iron reduction. Conclusions: These results provide physiological and biochemical evidences that UndA and MtrC of Shewanella putrefaciens W3-18-1 are involved in iron reduction.
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Combined genomics and experimental analyses of respiratory characteristics of Shewanella putrefaciens W3-18-1.
Applied and environmental microbiology, 2013Co-Authors: Dongru Qiu, Hehong Wei, Yunfeng Yang, Ming Xie, Jingrong Chen, Mark H. Pinkerton, Yili Liang, Jizhong ZhouAbstract:It has previously been shown that the Shewanella putrefaciens W3-18-1 strain produces remarkably high current in microbial fuel cells (MFCs) and can form magnetite at 0 degrees C. To explore the underlying mechanisms, we developed a genetic manipulation method by deleting the restriction-modification system genes of the SGI1 (Salmonella genome island 1)-like prophage and analyzed the key genes involved in bacterial respiration. W3-18-1 has less respiratory flexibility than the well-characterized S. oneidensis MR-1 strain, as it possesses fewer cytochrome c genes and lacks the ability to oxidize sulfite or reduce dimethyl sulfoxide (DMSO) and timethylamine oxide (TMAO). W3-18-1 lacks the hydrogen-producing Fe-only hydrogenase, and the hydrogen-oxidizing Ni-Fe hydrogenase genes were split into two separate clusters. Two periplasmic nitrate reductases (NapDAGHB and NapDABC) were functionally redundant in anaerobic growth of W3-18-1 with nitrate as the electron acceptor, though napDABC was not regulated by Crp. Moreover, nitrate respiration started earlier in W3-18-1 than in MR-1 (with NapDAGHB only) under microoxic conditions. These results indicate that Shewanella putrefaciens W3-18-1 is well adapted to habitats with higher oxygen levels. Taken together, the results of this study provide valuable insights into bacterial genome evolution.
