Anaerobic reduction of 2,6-dinitrotoluene by Shewanella oneidensis MR-1: Roles of Mtr respiratory pathway and NfnB

2016 ◽  
Vol 114 (4) ◽  
pp. 761-768 ◽  
Author(s):  
Dong-Feng Liu ◽  
Di Min ◽  
Lei Cheng ◽  
Feng Zhang ◽  
Dao-Bo Li ◽  
...  
Keyword(s):  
Shewanella Oneidensis ◽  
Respiratory Pathway ◽  
Anaerobic Reduction

scholarly journals The Mtr Respiratory Pathway Is Essential for Reducing Flavins and Electrodes in Shewanella oneidensis

2009 ◽  
Vol 192 (2) ◽  
pp. 467-474 ◽  
Author(s):  
Dan Coursolle ◽  
Daniel B. Baron ◽  
Daniel R. Bond ◽  
Jeffrey A. Gralnick
Keyword(s):  
Shewanella Oneidensis ◽  
Flavin Mononucleotide ◽  
Wild Type ◽  
Respiratory Pathway ◽  
Biologically Relevant ◽  
Electron Shuttles ◽  
Substrate Reduction ◽  
Oxidized Iron ◽  
Associated Proteins ◽  
Current Production

ABSTRACT The Mtr respiratory pathway of Shewanella oneidensis strain MR-1 is required to effectively respire both soluble and insoluble forms of oxidized iron. Flavins (riboflavin and flavin mononucleotide) recently have been shown to be excreted by MR-1 and facilitate the reduction of insoluble substrates. Other Shewanella species tested accumulated flavins in supernatants to an extent similar to that of MR-1, suggesting that flavin secretion is a general trait of the species. External flavins have been proposed to act as both a soluble electron shuttle and a metal chelator; however, at biologically relevant concentrations, our results suggest that external flavins primarily act as electron shuttles for MR-1. Using deletion mutants lacking various Mtr-associated proteins, we demonstrate that the Mtr extracellular respiratory pathway is essential for the reduction of flavins and that decaheme cytochromes found on the outer surface of the cell (MtrC and OmcA) are required for the majority of this activity. Given the involvement of external flavins in the reduction of electrodes, we monitored current production by Mtr respiratory pathway mutants in three-electrode bioreactors under controlled flavin concentrations. While mutants lacking MtrC were able to reduce flavins at 50% of the rate of the wild type in cell suspension assays, these strains were unable to grow into productive electrode-reducing biofilms. The analysis of mutants lacking OmcA suggests a role for this protein in both electron transfer to electrodes and attachment to surfaces. The parallel phenotypes of Mtr mutants in flavin and electrode reduction blur the distinction between direct contact and the redox shuttling strategies of insoluble substrate reduction by MR-1.

scholarly journals Mechanism and Consequences of Anaerobic Respiration of Cobalt by Shewanella oneidensis Strain MR-1

2008 ◽  
Vol 74 (22) ◽  
pp. 6880-6886 ◽  
Author(s):  
Heidi H. Hau ◽  
Alan Gilbert ◽  
Dan Coursolle ◽  
Jeffrey A. Gralnick
Keyword(s):  
Redox State ◽  
Molecular Mechanisms ◽  
Shewanella Oneidensis ◽  
Anaerobic Respiration ◽  
Electron Acceptors ◽  
Type Ii Secretion ◽  
Type Ii ◽  
Respiratory Pathway ◽  
By Products ◽  
State Of Metals

ABSTRACT Bacteria from the genus Shewanella are the most diverse respiratory organisms studied to date and can utilize a variety of metals and metal(loid)s as terminal electron acceptors. These bacteria can potentially be used in bioremediation applications since the redox state of metals often influences both solubility and toxicity. Understanding molecular mechanisms by which metal transformations occur and the consequences of by-products that may be toxic to the organism and thus inhibitory to the overall process is significant to future applications for bioremediation. Here, we examine the ability of Shewanella oneidensis to catalyze the reduction of chelated cobalt. We describe an unexpected ramification of [Co(III)-EDTA]− reduction by S. oneidensis: the formation of a toxic by-product. We found that [Co(II)-EDTA]2−, the product of [Co(III)-EDTA]− respiration, inhibited the growth of S. oneidensis strain MR-1 and that this toxicity was partially abolished by the addition of MgSO4. We demonstrate that [Co(III)-EDTA]− reduction by S. oneidensis requires the Mtr extracellular respiratory pathway and associated pathways required to develop functional Mtr enzymes (the c-type cytochrome maturation pathway) and ensure proper localization (type II secretion). The Mtr pathway is known to be required for a variety of substrates, including some chelated and insoluble metals and organic compounds. Understanding the full substrate range for the Mtr pathway is crucial for developing S. oneidensis strains as a tool for bioremediation.

Exemplar Abstract for Shewanella oneidensis Venkateswaran et al. 1999.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Shewanella Oneidensis

Review on Efficacy of Herbal Antiviral Drugs against COVID-19

2020 ◽  
Vol 11 (SPL1) ◽  
pp. 1116-1121
Author(s):  
Pooja P. Thakre ◽  
Vinod Ade ◽  
Shweta Parwe
Keyword(s):  
Physical Contact ◽  
Research Articles ◽  
Herbal Drugs ◽  
Plant Origin ◽  
Respiratory Pathway ◽  
Traditional Medicines ◽  
The Past ◽  
Primary Health ◽  
Coronavirus Infection ◽  
Novel Coronavirus

Coronavirus disease (CoViD-19) is an infection of the respiratory system caused due to various viruses affects the respiratory pathway, and it can spread from one person to another by coughing, sneezing or physical contact. Commonly include cough, cold, fever are the symptoms. Viral diseases increase worldwide concern, including emerging and chronic viruses. The invention of new anti-viral drugs from plants has implicit in the past. The Coronavirus disease 19 (COVID-19) caused due to severe acute respiratory syndrome, which is a transmittable and pathogenic viral infection. Several traditional medicines of plant origin having antimicrobial and anti-inflammatory properties some have been studied for their anti-viral properties and immune-modulating effects. Herbal drugs are now in massive requirement in the developing countries for primary health care not because of their economical but also for better civilising adequacy, improved compatibility with the human body and significantly fewer side effects. This review gives an overview of some critical traditionally used medicinal herbs with anti-viral properties—the literature regarding the drugs of this group, collected from Ayurveda classics. Research articles are collected from published material and discussed per therapeutic actions. Most of the Herbs are with Katu Rasa (pungent) and Ushna Virya (hot potency). They are indicated in diseases, viz. Kasa (cough), Shwas (asthma), Krumi (worm/ infection). Krumihara property drugs which are correlated with anti-viral action helps to prevent against Novel coronavirus infection.

A ROLE OF PROTEINS OF THE OUTER MEMBRANE OF Shewanella oneidensis MR-1 BACTERIA IN FORMATION AND STABILIZATION OF SILVER SULFIDE NANOPARTICLES

2015 ◽  
pp. 41-48 ◽  
Author(s):  
T. A. Voeikova ◽  
A. S. Shebanova ◽  
Yu. D. Ivanov ◽  
A. L. Kaysheva ◽  
L. M. Novikova ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Shewanella Oneidensis ◽  
Silver Sulfide ◽  
Silver Sulfide Nanoparticles
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