The exploration of the effective methods to evaluate the stripping ability of bacteriacide to SRB biofilm

2016 ◽  
Vol 63 (6) ◽  
pp. 445-451
Author(s):  
Yanan Wu ◽  
Hongfang Liu ◽  
Bijuan Zheng ◽  
Shuang Qin ◽  
Lei Chen
Keyword(s):  
Design Methodology ◽  
Electrochemical Impedance ◽  
Three Dimensional ◽  
Most Probable Number ◽  
Probable Number ◽  
Content Type ◽  
Sulfate Reducing ◽  
Effective Evaluation ◽  
Eis Measurements ◽  
Reducing Bacteria

Purpose The purpose of this paper was to study some effective evaluation methods for the biocide performance on sulfate-reducing bacteria (SRB) biofilm. Design/methodology/approach The most probable number method, electrochemical impedance spectroscopy (EIS) measurements, scanning electron microscopy (SEM), three-dimensional (3D) photos and epifluorescent microscopy were used in this study. Findings The results showed that the minimum inhibitory concentrations and minimum bactericidal concentrations of them to sessile SRB were greatly more than planktonic SRB. The EIS of the two biocides indicated that the biofilm exposed to higher concentrations of biocide were much more compact and flat, which perfectly coincided with the SEM, 3D photos and the epifluorescent microscopies. Originality/value In this paper, it, thus, appears that these methods evaluating biocide performance on the SRB biofilm were really effective by comparing the performance of bis-quaternary ammonium salt (BAQS) and tetrakis hydroxymethyl phosphonium sulfate.

Zwitterionic molecule layer for inhibiting microbial corrosion of copper alloy

2018 ◽  
Vol 65 (1) ◽  
pp. 46-52
Author(s):  
Fengling Xu ◽  
Zhenghui Qiu ◽  
Ri Qiu ◽  
Jiadong Yang ◽  
Cunguo Lin
Keyword(s):  
Electrochemical Impedance ◽  
Chemical Vapor ◽  
Attenuated Total Reflectance ◽  
Microbial Corrosion ◽  
Content Type ◽  
Sulfate Reducing ◽  
Angle Measurements ◽  
Static Contact ◽  
Contact Angle Measurements ◽  
Reducing Bacteria

Purpose For mitigating biocorrosion induced by sulfate-reducing bacteria (SRB) in seawater, the zwitterionic molecule layer (ZML) of poly (sulfobetaine methacrylate) is grafted onto B10 surface by chemical vapor deposition and surface-initiated atom transfer radical polymerization. Design/methodology/approach Energy-dispersive spectroscopy-attenuated total reflectance Fourier transform infrared spectroscopy and static contact angle measurements are used to characterize the as-formed layer. Findings After surface modification, B10 can significantly reduce SRB adhesion, demonstrating the good antifouling property. Further, the biocorrosion inhibition is investigated by potentiodynamic polarization and electrochemical impedance spectroscopy, indicating that ZML exhibits high resistance to biocorrosion with inhibition efficiency of approximately 90 per cent. Originality/value ZML performs a dual feature, i.e. antifouling film and corrosion inhibitor, for the biocorrosion inhibition.

Enumeration of selected bacterial populations in a high mountain watershed

1974 ◽  
Vol 20 (11) ◽  
pp. 1487-1492 ◽  
Author(s):  
Q. D. Skinner ◽  
J. C. Adams ◽  
P. A. Rechard ◽  
A. A. Beetle
Keyword(s):  
Sampling Site ◽  
Sulfate Reducing Bacteria ◽  
Most Probable Number ◽  
High Mountain ◽  
Probable Number ◽  
Sulfate Reducing ◽  
Mountain Watershed ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria ◽  
Stream Systems

Nitrate-reducing bacteria, sulfate-reducing bacteria, fluorescent bacteria, and the total viable count were enumerated in three stream systems within a high mountain watershed over a period of two winters and two summers from 1970 to 1972. Spread plate and most probable number procedures showed that the number of fluorescent bacteria, sulfate-reducing bacteria, nitrate-reducing bacteria, and the total count were generally constant throughout the year at the lowest sampling site on the stream systems. However, in some cases and for short periods of time, the numbers of these bacteria appeared to be influenced by recreational use of the land and stream flow. For example, denitrifying bacteria increased in number during the winter recreational period and gave the lowest counts in July.

Improved Most-Probable-Number Method To Detect Sulfate-Reducing Bacteria with Natural Media and a Radiotracer

1998 ◽  
Vol 64 (5) ◽  
pp. 1700-1707 ◽  
Author(s):  
Flemming Vester ◽  
Kjeld Ingvorsen
Keyword(s):  
Sulfate Reduction ◽  
Environmental Samples ◽  
Sulfate Reducing Bacteria ◽  
Most Probable Number ◽  
Probable Number ◽  
Sulfate Reducing ◽  
Sulfate Reduction Rates ◽  
Synthetic Media ◽  
Reducing Bacteria ◽  
Natural Media

ABSTRACT A greatly improved most-probable-number (MPN) method for selective enumeration of sulfate-reducing bacteria (SRB) is described. The method is based on the use of natural media and radiolabeled sulfate (35SO4 2−). The natural media used consisted of anaerobically prepared sterilized sludge or sediment slurries obtained from sampling sites. The densities of SRB in sediment samples from Kysing Fjord (Denmark) and activated sludge were determined by using a normal MPN (N-MPN) method with synthetic cultivation media and a tracer MPN (T-MPN) method with natural media. The T-MPN method with natural media always yielded significantly higher (100- to 1,000-fold-higher) MPN values than the N-MPN method with synthetic media. The recovery of SRB from environmental samples was investigated by simultaneously measuring sulfate reduction rates (by a35S-radiotracer method) and bacterial counts by using the T-MPN and N-MPN methods, respectively. When bacterial numbers estimated by the T-MPN method with natural media were used, specific sulfate reduction rates (qSO4 2−) of 10−14to 10−13 mol of SO4 2−cell−1 day−1 were calculated, which is within the range of qSO4 2− values previously reported for pure cultures of SRB (10−15 to 10−14 mol of SO4 2− cell−1day−1). qSO4 2− values calculated from N-MPN values obtained with synthetic media were several orders of magnitude higher (2 � 10−10 to 7 � 10−10 mol of SO4 2−cell−1 day−1), showing that viable counts of SRB were seriously underestimated when standard enumeration media were used. Our results demonstrate that the use of natural media results in significant improvements in estimates of the true numbers of SRB in environmental samples.

Influence of sulfate reducing bacteria on the cupronickel corrosion

2014 ◽  
Vol 61 (6) ◽  
pp. 395-401
Author(s):  
Liu Kecheng ◽  
Liu Xia ◽  
Long Xiao ◽  
Wei Jiaqiang ◽  
Hu Mengsha ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Polarization Resistance ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Sulfate Reducing Bacteria ◽  
Free Corrosion Potential ◽  
Content Type ◽  
Linear Polarization Resistance ◽  
Sulfate Reducing ◽  
Reducing Bacteria

Purpose – The purpose of this study is to explore the influence of the sulfate reducing bacteria (SRB) on the corrosion of cupronickel. Design/methodology/approach – Tests monitoring the change in free corrosion potential, linear polarization resistance and electrochemical impedance spectroscopy and examination using the scanning electron microscope and energy spectrum analysis were used to investigate the corrosion behavior of cupronickel in blank medium and in media inoculated with SRB to explore the influence of the SRB on the corrosion behavior of cupronickel alloy. Findings – The results show that SRB can destroy the surface oxide film of cupronickel and significantly reduce the free corrosion potential and polarization resistance of the cupronickel, causing the cupronickel to corrode significantly. Originality/value – SRB are widely found in the water supply system and is one of the important factors inducing microbial corrosion. This paper verified that SRB promote cupronickel corrosion and explored the influence and mechanism of attack.

scholarly journals Community Size and Metabolic Rates of Psychrophilic Sulfate-Reducing Bacteria in Arctic Marine Sediments

1999 ◽  
Vol 65 (9) ◽  
pp. 4230-4233 ◽  
Author(s):  
Christian Knoblauch ◽  
Bo Barker Jørgensen ◽  
Jens Harder
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Physiological Adaptation ◽  
Most Probable Number ◽  
Metabolic Rates ◽  
Community Size ◽  
Probable Number ◽  
Sulfate Reducers ◽  
Sulfate Reducing ◽  
Sulfate Reduction Rates ◽  
Reducing Bacteria

ABSTRACT The numbers of sulfate reducers in two Arctic sediments with in situ temperatures of 2.6 and −1.7°C were determined. Most-probable-number counts were higher at 10°C than at 20°C, indicating the predominance of a psychrophilic community. Mean specific sulfate reduction rates of 19 isolated psychrophiles were compared to corresponding rates of 9 marine, mesophilic sulfate-reducing bacteria. The results indicate that, as a physiological adaptation to the permanently cold Arctic environment, psychrophilic sulfate reducers have considerably higher specific metabolic rates than their mesophilic counterparts at similarly low temperatures.

scholarly journals Acetogenic and Sulfate-Reducing Bacteria Inhabiting the Rhizoplane and Deep Cortex Cells of the Sea Grass Halodule wrightii

1999 ◽  
Vol 65 (11) ◽  
pp. 5117-5123 ◽  
Author(s):  
Kirsten Küsel ◽  
Holly C. Pinkart ◽  
Harold L. Drake ◽  
Richard Devereux
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Epidermal Cells ◽  
Most Probable Number ◽  
Halodule Wrightii ◽  
Probable Number ◽  
Thin Sections ◽  
Sulfate Reducers ◽  
Sulfate Reducing ◽  
Sea Grass ◽  
Reducing Bacteria

ABSTRACT Recent declines in sea grass distribution underscore the importance of understanding microbial community structure-function relationships in sea grass rhizospheres that might affect the viability of these plants. Phospholipid fatty acid analyses showed that sulfate-reducing bacteria and clostridia were enriched in sediments colonized by the sea grasses Halodule wrightii andThalassia testudinum compared to an adjacent unvegetated sediment. Most-probable-number analyses found that in contrast to butyrate-producing clostridia, acetogens and acetate-utilizing sulfate reducers were enriched by an order of magnitude in rhizosphere sediments. Although sea grass roots are oxygenated in the daytime, colorimetric root incubation studies demonstrated that acetogenic O-demethylation and sulfidogenic iron precipitation activities were tightly associated with washed, sediment-free H. wrightii roots. This suggests that the associated anaerobes are able to tolerate exposure to oxygen. To localize and quantify the anaerobic microbial colonization, root thin sections were hybridized with newly developed 33P-labeled probes that targeted (i) low-G+C-content gram-positive bacteria, (ii) cluster I species of clostridia, (iii) species of Acetobacterium, and (iv) species of Desulfovibrio. Microautoradiography revealed intercellular colonization of the roots by Acetobacteriumand Desulfovibrio species. Acetogenic bacteria occurred mostly in the rhizoplane and outermost cortex cell layers, and high numbers of sulfate reducers were detected on all epidermal cells and inward, colonizing some 60% of the deepest cortex cells. Approximately 30% of epidermal cells were colonized by bacteria that hybridized with an archaeal probe, strongly suggesting the presence of methanogens. Obligate anaerobes within the roots might contribute to the vitality of sea grasses and other aquatic plants and to the biogeochemistry of the surrounding sediment.

Corrosion protection of coatings doped with inhibitor-loaded nanocapsules

2015 ◽  
Vol 62 (2) ◽  
pp. 88-94 ◽  
Author(s):  
Ahmad Khajouei ◽  
Effat Jamalizadeh ◽  
Seyed Mohammad Ali Hosseini
Keyword(s):  
Epoxy Resin ◽  
Corrosion Protection ◽  
Cationic Surfactants ◽  
Design Methodology ◽  
Electrochemical Impedance ◽  
Halloysite Nanotubes ◽  
Corrosion Activity ◽  
Protective Properties ◽  
Content Type ◽  
Eis Measurements

Purpose – The purpose of this paper was to study the corrosion resistance of AA2024 alloy using surfactant-modified halloysite nanocapsules capable of holding benzotriazole (BTA) as the corrosion inhibitor and discharging it into the solution. Design/methodology/approach – The effect of surfactant shells was studied by surfactant-modified halloysite nanotubes fabricated through assembly of two types of cationic surfactants. The zeta potential and size distribution measurements were performed using a Zetasizer Nano. The concentration of BTA during release into the solution was detected by using a UV–vis spectrophotometer. The anti-corrosion activity of nanocapsules as free agents with respect to the AA2024 alloy was investigated using the potentiodynamic scan (PDS) method. An epoxy resin doped with nanocapsules was used as an anti-corrosion coating deposited on the AA2024 alloy. The corrosion protection performance of coatings was studied by using the electrochemical impedance spectroscopy (EIS) method. Findings – The results indicate that the release of the inhibitor from nanocapsules depends on the surfactant shell components. The PDS results confirmed the feasibility of developing “smart” corrosion protection by inhibitor-loaded nanocapsules. The results of EIS measurements showed that the coating with the nanocapsules exhibited enhanced corrosion protection in comparison with the undoped coating. Originality/value – The findings of this paper indicate that surfactant-modified halloysite nanocapsules can be added to epoxy resin coatings to improve their corrosion protective properties for the AA2024 alloy.

scholarly journals Concentration of sheep manure bacteria in the immobilization of arsenic from groundwater using zero-valent

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Wahyu Wilopo ◽  
Keiko Sasaki ◽  
Tsuyoshi Hirajim
Keyword(s):  
Arsenic Concentration ◽  
Anaerobic Bacteria ◽  
Sulfate Reducing Bacteria ◽  
Permeable Reactive Barrier ◽  
Most Probable Number ◽  
Probable Number ◽  
Sulfate Reducing ◽  
Sheep Manure ◽  
Population Size Estimates ◽  
Reducing Bacteria

Permeable reactive barrier column tests were performed to investigate whether anaerobic bacteria in sheep manure could help remove As from groundwater. One column served as a control and was packed with zero-valent iron (ZVI), compost leaf, wood chips, glass beads, and gravel, after which it was sterilized. The other (‘inoculated column’) was packed with the same ingredients, with the addition of sheep manure as a source of anaerobic bacteria. Simulated As-contaminated groundwater was prepared based on groundwater samples from Sumbawa Island, Indonesia, but with the arsenic concentration adjusted to 50 mg/L. The inoculated column was found to remove As more effectively from the simulated groundwater than the sterilized one. A gradual decrease in sulfate concentration was observed in the inoculated column at the rate of 0.26 mmol of sulfate/L/day, suggesting that there was sulfate-reducing activity in the microbial population. In addition, the sulfur isotope ratio showed -4.3 (‰) and 0.2 (‰) in influent and effluent, respectively, indicating that sulfate-reducing bacteria (SRB) consumed δ32S preferentially. Using population size estimates from the most probable number (MPN) method, the population of SRB was found to increase with distance traveled in the column. Profiling the community composition of the bacteria in different fractions of the inoculated column using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) on 16S rRNA sequences suggested that a majority of bacteria were various Clostridium species and one species of Proteobacteria, Geobacter metallireducens GS-15. Some of them may contribute to the removal of arsenic.Keywords: Sheep manure, zero valence iron, arsenic, immobilization, sulfate-reducing bacteria

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