scholarly journals Analysis of Corrosion Defects on Oil Pipeline Surface Using Scanning Electron Microscopy and Soil Thionic and Sulfate-reducing Bacteria Quantification

2016 ◽  
Vol 152 ◽  
pp. 247-250 ◽  
Author(s):  
M.G. Chesnokova ◽  
V.V. Shalaj ◽  
Y.A. Kraus ◽  
N.V. Cherkashina ◽  
A.Yu. Mironov
2020 ◽  
Vol 82 (5) ◽  
pp. 11-20
Author(s):  
D.R. Abdulina ◽  
◽  
L.M. Purish ◽  
G.O. Iutynska ◽  
◽  
...  

The studies of the carbohydrate composition of the sulfate-reducing bacteria (SRB) biofilms formed on the steel surface, which are a factor of microbial corrosion, are significant. Since exopolymers synthesized by bacteria could activate corrosive processes. The aim of the study was to investigate the specificity of commercial lectins, labeled with colloidal gold to carbohydrates in the biofilm exopolymeric matrix produced by the corrosive-relevant SRB strains from man-caused ecotopes. Methods. Microbiological methods (obtaining of the SRB biofilms during cultivation in liquid Postgate B media under microaerophilic conditions), biochemical methods (lectin-binding analysis of 10 commercial lectins, labeled with colloidal gold), transmission electron microscopy using JEM-1400 JEOL. Results. It was shown using transmission electron microscopy that the binding of lectins with carbohydrates in the biofilm of the studied SRB strains occurred directly in the exopolymerіс matrix, as well as on the surfaces of bacterial cells, as seen by the presence of colloidal gold particles. For detection of the neutral carbohydrates (D-glucose and D-mannose) in the biofilm of almost all studied bacterial strains PSA lectin was the most specific. This lectin binding in biofilms of Desulfotomaculum sp. К1/3 and Desulfovibrio sp. 10 strains was higher in 90.8% and 94.4%, respectively, then for ConA lectin. The presence of fucose in the SRB biofilms was detected using LABA lectin, that showed specificity to the biofilm EPS of all the studied strains. LBA lectin was the most specific to N-аcetyl-D-galactosamine for determination of amino sugars in the biofilm. The amount of this lectin binding in D. vulgaris DSM644 biofilm was 30.3, 10.1 and 9.3 times higher than SBA, SNA and PNA lectins, respectively. STA, LVA and WGA lectins were used to detect the N-acetyl-Dglucosamine and sialic acid in the biofilm. WGA lectin showed specificity to N-acetyl-D-glucosamine in the biofilm of all the studied SRB; maximum number of bounded colloidal gold particles (175 particles/μm2) was found in the Desulfotomaculum sp. TC3 biofilm. STA lectin was interacted most actively with N-acetyl-D-glucosamine in Desulfotomaculum sp. TC3 and Desulfomicrobium sp. TC4 biofilms. The number of bounded colloidal gold particles was in 9.2 and 7.4 times higher, respectively, than using LVA lectin. The lowest binding of colloidal gold particles was observed for LVA lectin. Conclusions. It was identified the individual specificity of the 10 commercial lectins to the carbohydrates of biofilm matrix on the steel surface, produced by SRB. It was estimated that lectins with identical carbohydrates specificity had variation in binding to the biofilm carbohydrates of different SRB strains. Establishing of the lectin range selected for each culture lead to the reduction of the scope of studies and labor time in the researching of the peculiarities of exopolymeric matrix composition of biofilms formed by corrosiverelevant SRB.


1990 ◽  
Vol 36 (6) ◽  
pp. 400-408 ◽  
Author(s):  
Judy D. Wall ◽  
Barbara J. Rapp-Giles ◽  
Merton F. Brown ◽  
Jerry A. White

Oxygen tolerance of the strictly anaerobic sulfate-reducing bacteria is well documented and poorly understood. This capacity for surviving brief exposures to oxygen must be a major factor in the diversity of environmental niches observed for these bacteria. We observed that viable cells of Desulfovibrio desulfuricans (ATCC 27774) could be found in colonies on the surface of solidified medium exposed to air for periods as long as 1 month. During exposure to air, the originally black colonies became greyish white, presumably as a result of the air oxidation of the metal sulfide deposits. A black, brittle deposit formed at the bottom of the colony and, simultaneously, the colony descended into a dimple that developed into a well in the agar. Eventually the colony reached the bottom of the Petri dish. These changes did not take place when the colonies were maintained in an anaerobic chamber. The morphological changes took place with all strains tested: three strains of D. desulfuricans and one strain of Desulfovibrio gigas and Desulfovibrio multispirans. Continued sulfate reduction appeared to be essential. Cyclic sulfate (thiosulfate or sulfite) reduction to sulfide and reoxidation of sulfide by the oxygen in air are proposed to maintain the viability of the bacteria by providing substrates for energy production and by reducing oxygen tension. Scanning and transmission electron microscopy of colony and cellular changes are shown. Key words: Desulfovibrio, sulfate-reducing bacteria, oxygen tolerance, sulfate cycling, scanning electron microscopy.


2003 ◽  
Vol 69 (12) ◽  
pp. 7063-7072 ◽  
Author(s):  
Simon L. Hockin ◽  
Geoffrey M. Gadd

ABSTRACT A biofilm-forming strain of sulfate-reducing bacteria (SRB), isolated from a naturally occurring mixed biofilm and identified by 16S rDNA analysis as a strain of Desulfomicrobium norvegicum, rapidly removed 200 μM selenite from solution during growth on lactate and sulfate. Elemental selenium and elemental sulfur were precipitated outside SRB cells. Precipitation occurred by an abiotic reaction with bacterially generated sulfide. This appears to be a generalized ability among SRB, arising from dissimilatory sulfide biogenesis, and can take place under low redox conditions and in the dark. The reaction represents a new means for the deposition of elemental sulfur by SRB under such conditions. A combination of transmission electron microscopy, environmental scanning electron microscopy, and cryostage field emission scanning electron microscopy were used to reveal the hydrated nature of SRB biofilms and to investigate the location of deposited sulfur-selenium in relation to biofilm elements. When pregrown SRB biofilms were exposed to a selenite-containing medium, nanometer-sized selenium-sulfur granules were precipitated within the biofilm matrix. Selenite was therefore shown to pass through the biofilm matrix before reacting with bacterially generated sulfide. This constitutes an efficient method for the removal of toxic concentrations of selenite from solution. Implications for environmental cycling and the fate of sulfur and selenium are discussed, and a general model for the potential action of SRB in selenium transformations is presented.


2018 ◽  
Vol 64 (9) ◽  
pp. 629-637 ◽  
Author(s):  
William Stanley ◽  
Gordon Southam

Growth of two dissimilatory sulfate-reducing bacteria, Desulfosporosinus orientis (gram-positive) and Desulfovibrio desulfuricans (gram-negative), in a chemically defined culture medium resulted in similar growth rates (doubling times for each culture = 2.8 h) and comparable rates of H2S generation (D. orientis = 0.19 nmol/L S2–per cell per h; D. desulfuricans = 0.12 nmol/L S2–per cell per h). Transmission electron microscopy of whole mounts and thin sections revealed that the iron sulfide mineral precipitates produced by the two cultures were morphologically different. The D. orientis culture flocculated, with the minerals occurring as subhedral plate-like precipitates, which nucleated on the cell wall during exponential growth producing extensive mineral aggregates following cell autolysis and endospore release. In contrast, the D. desulfuricans culture produced fine-grained colloidal or platy iron sulfide precipitates primarily within the bulk solution. Mineral analysis by scanning electron microscopy – energy dispersive spectroscopy indicated that neither culture promoted advanced mineral development beyond a 1:1 Fe:S stoichiometry. This analysis did not detect pyrite (FeS2). The average Fe:S ratios were 1 : 1.09 ± 0.03 at 24 h and 1 : 1.08 ± 0.03 at 72 h for D. orientis and 1 : 1.05 ± 0.02 at 24 h and 1 : 1.09 ± 0.07 at 72 h for D. desulfuricans. The formation of “biogenic” iron sulfides by dissimilatory sulfate-reducing bacteria is influenced by bacterial cell surface structure, chemistry, and growth strategy, i.e., mineral aggregation occurred with cell autolysis of the gram-positive bacterium.


2020 ◽  
Vol 9 (4) ◽  
pp. 125-131
Author(s):  
Ekaterina Vyacheslavovna Nesterova ◽  
Ekaterina Aleksandrovna Borisenkova ◽  
Nataliya Vladimirovna Prokhorova

The paper presents the results of model laboratory experiments carried out to assess the influence of oil microbocenosis bacteria on the corrosion process on the internal surfaces of oil pipelines made of steel 17G1S. It is known that the bacteria of this group most often include hydrocarbon-oxidizing bacteria (HOB), sulfate-reducing bacteria (SRB), sulfur-oxidizing, or thionic (TB) and iron-oxidizing bacteria (IOB). In model experiments with 17G1S steel samples alloyed with 1% manganese we used corrosion-hazardous bacteria of the genera Desulfotomaculum, Paracoccus, Pseudomonas and Sphaerotilus, isolated from a damaged section of an oil pipeline at a field in the northern part of the Samara Region. In the initial phase of the experiment, the titer of the analyzed bacteria was quite high (SRB 10⁴10⁵, TB 1010⁴ cells/cm), but by the end of the experiment, only sulfate-reducing bacteria with quantitative characteristics of 110 cells/cm were isolated from the culture liquid, may be due to the high adhesion capacity of mass cultures of the bacteria. On the surface of the steel samples the method of electron microscopy revealed unevenly distributed loose deposits, but the cells of the bacteria themselves were not visible in them. The morphological features of the revealed corrosion deposits indicated their bacterial origin, which was also confirmed by biochemical analysis of corrosion products suspension, in particular, by revealing a high mass concentration of sulfides, protein, and the dehydrogenase. Aerobic and anaerobic microbiological interactions occurring in the oil microbocenosis on the internal surfaces of pipelines have been experimentally confirmed and are in good agreement with the data of other researchers. It has been established that the main role in the corrosion destruction steel samples belongs to SRB, whose participation can be carried out according to two main mechanisms: hydrogen cracking and anodic dissolution of iron. Pits and through holes are formed on the steel surface, and the local corrosion rate can approaches 7,3 mm/year. The experiments proved the active role of oil microbocenoses, the basis of the microbiont of which consists of four bacteria, in the rapid destruction of oil pipelines in the Samara Region.


2011 ◽  
Vol 199-200 ◽  
pp. 102-105
Author(s):  
Xiao Dong Zhao ◽  
Jie Yang ◽  
Xi Qiu Fan

A kind of sulfate-reducing bacteria was isolated from the actual marine environment, cultured and enriched for phylogenetic analysis by molecular biology methods, and observed under fluorescent microscopy and transmission electron microscopy to determine the species and morphology. Taking the bacteria as the main object, the influenced corrosion behavior of steels in marine environment was studied in follow-up experiments.


Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.


Author(s):  
P.J. Dailey

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.


Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).


Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.


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