scholarly journals Uniform and Pitting Corrosion of Carbon Steel byShewanella oneidensisMR-1 under Nitrate-Reducing Conditions

2018 ◽  
Vol 84 (12) ◽  
pp. e00790-18 ◽  
Author(s):  
Robert B. Miller ◽  
Kenton Lawson ◽  
Anwar Sadek ◽  
Chelsea N. Monty ◽  
John M. Senko
Keyword(s):  
Electron Transfer ◽  
Carbon Steel ◽  
Electron Donor ◽  
Pitting Corrosion ◽  
Nitrate Reduction ◽  
Steel Corrosion ◽  
Nitrite Accumulation ◽  
Content Type ◽  
Microbially Influenced Corrosion ◽  
Reducing Conditions

ABSTRACTDespite observations of steel corrosion in nitrate-reducing environments, processes of nitrate-dependent microbially influenced corrosion (MIC) remain poorly understood and difficult to identify. We evaluated carbon steel corrosion byShewanella oneidensisMR-1 under nitrate-reducing conditions using a split-chamber/zero-resistance ammetry (ZRA) technique. This approach entails the deployment of two metal (carbon steel 1018 in this case) electrodes into separate chambers of an electrochemical split-chamber unit, where the microbiology or chemistry of the chambers can be manipulated. This approach mimics the conditions of heterogeneous metal coverage that can lead to uniform and pitting corrosion. The current between working electrode 1 (WE1) and WE2 can be used to determine rates, mechanisms, and, we now show, extents of corrosion. WhenS. oneidensiswas incubated in the WE1 chamber with lactate under nitrate-reducing conditions, nitrite transiently accumulated, and electron transfer from WE2 to WE1 occurred as long as nitrite was present. Nitrite in the WE1 chamber (withoutS. oneidensis) induced electron transfer in the same direction, indicating that nitrite cathodically protected WE1 and accelerated the corrosion of WE2. WhenS. oneidensiswas incubated in the WE1 chamber without an electron donor, nitrate reduction proceeded, and electron transfer from WE2 to WE1 also occurred, indicating that the microorganism could use the carbon steel electrode as an electron donor for nitrate reduction. Our results indicate that under nitrate-reducing conditions, uniform and pitting carbon steel corrosion can occur due to nitrite accumulation and the use of steel-Fe(0) as an electron donor, but conditions of sustained nitrite accumulation can lead to more-aggressive corrosive conditions.IMPORTANCEMicrobially influenced corrosion (MIC) causes damage to metals and metal alloys that is estimated to cost over $100 million/year in the United States for prevention, mitigation, and repair. While MIC occurs in a variety of settings and by a variety of organisms, the mechanisms by which microorganisms cause this damage remain unclear. Steel pipe and equipment may be exposed to nitrate, especially in oil and gas production, where this compound is used for corrosion and “souring” control. In this paper, we show uniform and pitting MIC under nitrate-reducing conditions and that a major mechanism by which it occurs is via the heterogeneous cathodic protection of metal surfaces by nitrite as well as by the microbial oxidation of steel-Fe(0).

scholarly journals Direct Electron Transfer between the frhAGB-Encoded Hydrogenase and Thioredoxin Reductase in the Nonmethanogenic Archaeon Thermococcus onnurineus NA1

2020 ◽  
Vol 86 (6) ◽  
Author(s):  
Hae-Chang Jung ◽  
Jae Kyu Lim ◽  
Tae-Jun Yang ◽  
Sung Gyun Kang ◽  
Hyun Sook Lee
Keyword(s):  
Electron Transfer ◽  
Electron Donor ◽  
Direct Electron Transfer ◽  
Thioredoxin Reductase ◽  
Thermococcus Onnurineus Na1 ◽  
Content Type ◽  
Protein Target ◽  
Redox Partner ◽  
Significant Step

ABSTRACT To date, NAD(P)H, ferredoxin, and coenzyme F420 have been identified as electron donors for thioredoxin reductase (TrxR). In this study, we present a novel electron source for TrxR. In the hyperthermophilic archaeon Thermococcus onnurineus NA1, the frhAGB-encoded hydrogenase, a homolog of the F420-reducing hydrogenase of methanogens, was demonstrated to interact with TrxR in coimmunoprecipitation experiments and in vitro pulldown assays. Electrons derived from H2 oxidation by the frhAGB-encoded hydrogenase were transferred to TrxR and reduced Pdo, a redox partner of TrxR. Interaction and electron transfer were observed between TrxR and the heterodimeric hydrogenase complex (FrhAG) as well as the heterotrimeric complex (FrhAGB). Hydrogen-dependent reduction of TrxR was 7-fold less efficient than when NADPH was the electron donor. This study not only presents a different type of electron donor for TrxR but also reveals new functionality of the frhAGB-encoded hydrogenase utilizing a protein as an electron acceptor. IMPORTANCE This study has importance in that TrxR can use H2 as an electron donor with the aid of the frhAGB-encoded hydrogenase as well as NAD(P)H in T. onnurineus NA1. Further studies are needed to explore the physiological significance of this protein. This study also has importance as a significant step toward understanding the functionality of the frhAGB-encoded hydrogenase in a nonmethanogen; the hydrogenase can transfer electrons derived from oxidation of H2 to a protein target by direct contact without the involvement of an electron carrier, which is distinct from the mechanism of its homologs, F420-reducing hydrogenases of methanogens.

Wood derived biochar as electron donor and its influence on microbial denitrification: Role of extracellular polymeric substances in extracellular electron transfer

2020 ◽  
Author(s):  
Kuppusamy Sathishkumar ◽  
Yi Li ◽  
Rana Muhammad Adnan Ikram
Keyword(s):  
Electron Transfer ◽  
Electron Donor ◽  
Electrochemical Behavior ◽  
Nitrate Reduction ◽  
Extracellular Polymeric Substances ◽  
Electrochemical Impedance ◽  
Electrochemical Analysis ◽  
Extracellular Electron Transfer ◽  
Microbial Denitrification

<p>Biochar is extensively used in environmental pollutant remediation because of its diverse property, however the effect of biochar on microbial nitrate reduction and electrochemical behavior of biochar remain unknown. Also electron transfer from the microbial cells to electron donor or acceptor have been transport across the extracellular polymeric substances (EPS), however it was unclear whether extracellular polymeric substances captured or enhance the electrons.  Hence, aim of the present study is to investigate the electrochemical behavior of biochar and its effects on microbial nitrate reduction and elucidate the role of extracellular polymeric substances in extracellular electron transfer (EET).  The biochar was prepared at different pyrolysis temperatures (400 °C, 500 °C and 600 °C) and their electrochemical behavior was characterized by electrochemical analysis (cyclic voltammetry, electrochemical impedance spectrum, chronoamperometry). Results demonstrated that all the biochars could donate and accept the electrons, impact of biochar on microbial nitrate reduction was studied and the results showed that biochar prepared at 400 °C significantly enhances microbial nitrate reduction process. Phenol O-H and quinone C=O surface functional groups on the biochar contributes in the overall electron exchange which accelerated the nitrate reduction. The role of EPS in EET by electrochemical analysis results reveals that outer membrane c-type cytochrome and flavin protein from the biofilm was involved in electron transfer process, and EPS act as transient media for microbial EET. Overall, present study suggested that biochar could be used as eco-friendly material for the enhancement of microbial denitrification.</p>

Effects of sulfide on mixotrophic denitrification by Thauera-dominated denitrifying sludge

2020 ◽  
Vol 6 (4) ◽  
pp. 1186-1195 ◽  
Author(s):  
Zhensheng Liang ◽  
Jianliang Sun ◽  
Chungeng Zhan ◽  
Siting Wu ◽  
Liang Zhang ◽  
...  
Keyword(s):  
Electron Donor ◽  
Nitrate Reduction ◽  
Nitrite Accumulation

Cultivation of Thauera-dominated denitrifying sludge can improve nitrate reduction with sulfide impacts, but nitrite accumulation should be considered when using sulfide as a complementary electron donor to treat wastewater with a low C/N ratio.

scholarly journals Bulk phase resource ratio alters carbon steel corrosion rates and endogenously produced extracellular electron transfer mediators in a sulfate-reducing biofilm

Biofouling ◽  
2019 ◽  
Vol 35 (6) ◽  
pp. 669-683 ◽  
Author(s):  
Gregory P. Krantz ◽  
Kilean Lucas ◽  
Erica L.- Wunderlich ◽  
Linh T. Hoang ◽  
Recep Avci ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Carbon Steel ◽  
Steel Corrosion ◽  
Bulk Phase ◽  
Extracellular Electron Transfer ◽  
Sulfate Reducing ◽  
Corrosion Rates

Polarization Behavior of Steel Corrosion in Laterite, Yellow Soil and Kaolin

2014 ◽  
Vol 1025-1026 ◽  
pp. 656-660
Author(s):  
Rita Sundari ◽  
Amy Wahida Mohamad Sa'adan
Keyword(s):  
Carbon Steel ◽  
Soil Solution ◽  
Pitting Corrosion ◽  
Economic Value ◽  
Steel Corrosion ◽  
Great Loss ◽  
Polarization Behavior ◽  
Underground Pipelines ◽  
Thermodynamic Effect ◽  
Corrosive Effect

Corrosion of buried pipelines caused by aging process has taken serious problems. Pitting corrosion in underground pipelines may yield material damage causing great loss of economic value and therefore, this study has emphasized on carbon steel corrosion in three types of soil (laterite, yellow soil and kaolin). Yellow soil solution performed remarkable polarization behavior compared to laterite and kaolin solutions on the basis of Tafel plot. Corrosion potentials of – 0.36V, – 0.47V and – 0.35V were showed by carbon steel corrosion in laterite, yellow soil and kaolin solutions. Yellow soil solution also performed the most corrosive effect on carbon steel due to temperature effect (30o– 90oC). In addition, the corrosion of carbon steel in yellow soil solution posed the lowest enthalpy with regard to thermodynamic effect. This study also showed that the carbon steel corrosion in laterite solution referred to pitting corrosion based on linear adsorption isotherm. This investigation gives valuable information with respect to underground pipelines corrosion.

An Inhibitive Effect of Aeration on the Pitting Corrosion of Steels in Ethanolic Environments

CORROSION ◽  
10.5006/4000 ◽  
2021 ◽  
Author(s):  
Ali Ashrafriahi ◽  
Anatolie Carcea ◽  
Roger Newman
Keyword(s):  
Carbon Steel ◽  
Pitting Corrosion ◽  
Surface Film ◽  
Steel Corrosion ◽  
Open Circuit ◽  
Localized Corrosion ◽  
Potential Measurement ◽  
Pitting Corrosion Resistance ◽  
Cyclic Potentiodynamic Polarization ◽  
Passivation Potential

This work is aimed at improving the understanding of the localized corrosion of carbon steel in ethanolic solutions. The role of ethanol dehydration, chloride, and oxygen level in the pitting behaviour of carbon steel in ethanolic environments in the presence of supporting electrolytes was investigated. Open Circuit Potential measurement, Cyclic Potentiodynamic Polarization and Potentiostatic testing were conducted on specimens exposed to ethanolic environments prepared from pure dehydrated ethanol to study the pitting behaviour of carbon steel. Corrosion and passivation potentials significantly reduce due to the change in the cathodic reaction and the decrease in passivation kinetics under de-aerated conditions. SEM and EDX examination indicated that no pitting corrosion is observed without chlorides, and chloride significantly destabilizes the surface film resulting in decreases of both corrosion potential and passivation potential. A decrease in the dissolved oxygen in the solution reduces but does not eliminate the pitting susceptibility. Iron oxide is identified as the significant corrosion product at different water and oxygen content. Therefore, ethanol aeration can be a proper method to increase pitting corrosion resistance in ethanolic solutions.

The influence of temperature on the inhibition of carbon steel corrosion in acidic lignin

2015 ◽  
Vol 62 (5) ◽  
pp. 301-306 ◽  
Author(s):  
Solhan Yahya ◽  
Norinsan Kamil Othman ◽  
Abdul Razak Daud ◽  
Azman Jalar ◽  
Roslina Ismail
Keyword(s):  
Weight Loss ◽  
Carbon Steel ◽  
Corrosion Inhibitor ◽  
Acid Corrosion ◽  
Steel Corrosion ◽  
Inhibition Mechanism ◽  
Free Energy Of Adsorption ◽  
Lignin Concentration ◽  
Content Type ◽  
Influence Of Temperature

Purpose – This paper aims to investigate the influence of temperature and lignin concentration on the inhibition of carbon steel corrosion in 1 M HCl. Design/methodology/approach – Weight loss corrosion tests were performed at different temperatures in the range of 30-70°C (303-343 K). Findings – It was found that the corrosion inhibition efficiency (IE) of lignin on the carbon steel decreased when the temperature was increased from 60 to 70°C. However, at lower temperatures ranging from 30 to 50°C, the IE improved, due to occurrence of lignin adsorption on the surface of metal specimens. The IE was higher with increasing lignin concentration, thus reducing the weight loss of the carbon steel. The adsorption phenomenon involved exothermic processes because the value of enthalpy of adsorption (ΔH°ads) < 0 and Gibbs free energy of adsorption (ΔG°ads) were less negative with increase in temperature. The entropy of adsorption (ΔS°ads) had negative values, representing the decrease in disorder of adsorption. The adsorption of lignin on the carbon steel surface in 1 M HCl was comprehensive, as deduced from kinetic and thermodynamic parameters. However, physisorption was the major contributor in the inhibition mechanism. The inhibitive features of carbon steel surfaces showed less damage once the steel was treated in lignin, as evident from macroscopy images. Practical implications – The use of lignin as an acid corrosion inhibitor at high temperature is practical in metal surface treatment process. Social implications – The use of organic compounds gives an advantage to the environment, universal health and save cost, as the compounds can be found in nature. Originality/value – Lignin can act as a flexible corrosion inhibitor within the temperature range of 30-70°C in 1 M HCl because it exhibits comprehensive adsorption (i.e. a combination of both physisorption and chemisorption) at specific concentrations.

scholarly journals Dissimilatory Nitrate Reduction to Ammonium (DNRA) and Denitrification Pathways Are Leveraged by Cyclic AMP Receptor Protein (CRP) Paralogues Based on Electron Donor/Acceptor Limitation in Shewanella loihica PV-4

2020 ◽  
Vol 87 (2) ◽  
Author(s):  
Shuangyuan Liu ◽  
Jingcheng Dai ◽  
Hehong Wei ◽  
Shuyang Li ◽  
Pei Wang ◽  
...  
Keyword(s):  
Global Warming ◽  
Carbon Source ◽  
Cyclic Amp ◽  
Electron Donor ◽  
Electron Acceptor ◽  
Nitrite Reductase ◽  
Nitrate Reduction ◽  
Receptor Protein ◽  
Content Type ◽  
Dissimilatory Nitrate Reduction

ABSTRACT Under anoxic conditions, many bacteria, including Shewanella loihica strain PV-4, could use nitrate as an electron acceptor for dissimilatory nitrate reduction to ammonium (DNRA) and/or denitrification. Previous and current studies have shown that DNRA is favored under higher ambient carbon-to-nitrogen (C/N) ratios, whereas denitrification is upregulated under lower C/N ratios, which is consistent with our bioenergetics calculations. Interestingly, computational analyses indicate that the common cyclic AMP receptor protein (designated CRP1) and its paralogue CRP2 might both be involved in the regulation of two competing dissimilatory nitrate reduction pathways, DNRA and denitrification, in S. loihica PV-4 and several other denitrifying Shewanella species. To explore the regulatory mechanism underlying the dissimilatory nitrate reduction (DNR) pathways, nitrate reduction of a series of in-frame deletion mutants was analyzed under different C/N ratios. Deletion of crp1 could accelerate the reduction of nitrite to NO under both low and high C/N ratios. CRP1 is not required for denitrification and actually suppresses production of NO and N2O gases. Deletion of either of the NO-forming nitrite reductase genes nirK or crp2 blocked production of NO gas. Furthermore, real-time PCR and electrophoretic mobility shift assays (EMSAs) demonstrated that the transcription levels of DNRA-relevant genes such as nap-β (napDABGH), nrfA, and cymA were upregulated by CRP1, while nirK transcription was dependent on CRP2. There are tradeoffs between the different physiological roles of nitrate/lactate, as nitrogen nutrient/carbon source and electron acceptor/donor and CRPs may leverage dissimilatory nitrate reduction pathways for maximizing energy yield and bacterial survival under ambient environmental conditions. IMPORTANCE Some microbes utilize different dissimilatory nitrate reduction (DNR) pathways, including DNR to ammonia (DNRA) and denitrification pathways, for anaerobic respiration in response to ambient carbon/nitrogen ratio changes. Large-scale industrial nitrogen fixation and fertilizer application raise the concern of emission of N2O, a stable gas with potent global warming potential, as consequence of microbial respiration, thereby aggravating global warming and climate change. However, little is known about the molecular mechanism underlying the choice of two competing DNR pathways. We demonstrate that the global regulator CRP1, which is widely encoded in bacteria, is required for DNRA in S. loihica PV-4 strain, while the CRP2 paralogue is required for transcription of the nitrite reductase gene nirK for denitrification. Sufficient carbon source lead to the predominance of DNRA, while carbon source/electron donor deficiency may result in an incomplete denitrification process, raising the concern of high levels of N2O emission from nitrate-rich and carbon source-poor waters and soils.

scholarly journals Biofilm Formation Plays a Crucial Rule in the Initial Step of Carbon Steel Corrosion in Air and Water Environments

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 923 ◽  
Author(s):  
Akiko Ogawa ◽  
Keito Takakura ◽  
Nobumitsu Hirai ◽  
Hideyuki Kanematsu ◽  
Daisuke Kuroda ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Thermal Spray ◽  
Biofilm Formation ◽  
Zinc Coating ◽  
Electrochemical Corrosion ◽  
Spray Coating ◽  
Steel Corrosion ◽  
Thermal Spray Coating ◽  
Iron Corrosion ◽  
Microbially Influenced Corrosion

In this study, we examined the relationship between the effect of a zinc coating on protecting carbon steel against biofilm formation in both air and water environments. SS400 carbon steel coupons were covered with a zinc thermal spray coating or copper thermal spray coating. Coated coupons were exposed to either air or water conditions. Following exposure, the surface conditions of each coupon were observed using optical microscopy, and quantitatively analyzed using an x-ray fluorescence analyzer. Debris on the surface of the coupons was used for biofilm analysis including crystal violet staining for quantification, Raman spectroscopic analysis for qualification, and microbiome analysis. The results showed that the zinc thermal spray coating significantly inhibited iron corrosion as well as biofilm formation in both air and water environments. The copper thermal spray coating, however, accelerated iron corrosion in both air and water environments, but accelerated biofilm formation only in a water environment. microbially-influenced-corrosion-related bacteria were barely detected on any coupons, whereas biofilms were detected on all coupons. To summarize these results, electrochemical corrosion is dominant in an air environment and microbially influenced corrosion is strongly involved in water corrosion. Additionally, biofilm formation plays a crucial rule in carbon steel corrosion in both air and water, even though microbially-influenced-corrosion-related bacteria are barely involved in this corrosion.

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