Search Results (74)

Microorganisms take an active part in the processes of microbiologically influenced corrosion, which is protected against by using bactericides—often toxic compounds—with inhibitory properties. There are many studies of eco-friendly “green” biocides/inhibitors, in particular those based on microbial metabolites. Indicators for the processes of microbial corrosion of steel 3 induced by the sulfate-reducing bacteria Desulfovibrio oryzae NUChC SRB2 under the influence of the strains Bacillus velezensis NUChC C2b and Streptomyces gardneri ChNPU F3 have not been investigated, which was the aim of this study. The agar well diffusion method (to determine the antibacterial properties of the supernatants) was used, along with the crystal violet (to determine the biomass of the biofilm on the steel) and gravimetric methods (to determine the corrosion rate). A moderate adhesiveness to steel 3 was established for D. oryzae due to its biofilm-forming ability. The presence of a supernatant on cultures of S. gardneri, B. velezensis and their mixture (2:1) did not reduce the biofilm-forming properties of D. oryzae. Compared to the control, a decrease in the corrosion rate was recorded for the variant of the mixture of the studied bacterial culture supernatants. This indicates the potential of this mixture for use in corrosion protection in environments with sulfate-reducing bacteria, which requires further research. Full article

Microbiologically influenced corrosion (MIC) poses significant challenges in oilfield water injection environments, leading to substantial socioeconomic losses. L245 steel, a low-alloy steel widely used in oil and gas pipelines due to its excellent mechanical properties and cost-effectiveness, remains highly vulnerable to MIC during long-term service. This study uses surface characterization and electrochemical techniques to investigate the corrosion behavior of L245 pipeline steel under short-cycle conditions in a symbiotic environment of iron-oxidizing bacteria (IOB) and Shewanella algae (S. algae). Key findings revealed that localized corrosion of L245 steel was markedly exacerbated under coexisting IOB and S. algae conditions compared to monoculture systems. However, the uniform corrosion rate under symbiosis fell between the rates observed in the individual IOB and S. algae systems. Mechanistically, the enhanced corrosion under symbiotic conditions was attributed to the synergistic electron transfer interaction: IOB exploited electron carriers secreted by S. algae during extracellular electron transfer (EET), which amplified the microbial consortium’s capacity to harvest electrons from the steel substrate. These results emphasize the critical role of interspecies electron exchange in accelerating localized degradation of carbon steel under complex microbial consortia, with implications for developing targeted mitigation strategies in industrial pipelines exposed to similar microbiological environments. Full article

Desulfovibrio vulgaris is an anaerobic microorganism belonging to the group of sulphate-reducing bacteria (SRB). SRB form biofilms on metal surfaces in water supply networks, producing a microbiologically influenced corrosion (MIC). This process produces the deterioration of metal surfaces, leading to high economic costs and different environmental safety and health problems related to its chemical treatment. For that reason, rapid and accurate detection methods of SRB are needed. In this work, a new detection system for Desulfovibrio has been developed using gated nanoporous materials. The probe is based on hybrid nanoporous alumina films encapsulating a fluorescent molecule (rhodamine B), whose release is controlled by an oligonucleotide gate. Upon exposure to Desulfovibrio’s genomic material, a movement of the oligonucleotide gatekeeper happens, resulting in the selective delivery of the entrapped rhodamine B. The developed material shows high selectivity and sensitivity for detecting Desulfovibrio DNA in aqueous buffer and biological media. The implementation of this technology for the detection of Desulfovibrio as a tool for monitoring water supply networks is innovative and allows real-time in situ monitoring, making it possible to detect the growth of Desulfovibrio inside of pipes at an early stage and perform timely interventions to reverse it. Full article

Zirconia crowns are employed in pediatric dentistry for the complete restoration of anterior and posterior deciduous teeth. They are considered the best option due to their esthetic appeal, high strength, biocompatibility, and resistance to wear and corrosion. This study aims to evaluate the physico-chemical, cytological, and microbial properties of zirconia crowns to determine their biocompatibility, safety for surrounding tissues, and effectiveness in preventing microbial influence on tooth tissue based on their biofilm deposition potential. XRD measurements were conducted to confirm the crown composition. For the microbiological examination, a quantitative assessment of the adhesion capacity of the analyzed strains and the formation of a mixed biofilm was performed using a Zeiss Cell Observer SD confocal microscope. This study used a mixed biofilm containing Streptococcus mutans (ATCC 25175), Lactobacillus rhamnosus (ATCC 9595), Candida albicans (ATCC 90028), and Candida albicans (ATCC 10231) to simulate the oral environment and the possible dynamics created between different types of microorganisms. A direct contact method was used to assess cytotoxic properties. The zirconia crown biomaterial shows a low ability to adhere to specific microorganisms, with L. rhamnosus predominating, indicating low clinical potential for causing inflammation of the tissues surrounding the crown. The cytotoxic properties of the biomaterial were found to be at level 2, indicating moderate cytotoxicity. Their biggest flaws are price and the need for passive fitting, which involves aggressive grinding; this is a potential limitation when it occurs in children, as their cooperation with the treatment can be difficult to guarantee. Full article

Microbiologically influenced corrosion (MIC) is one of the key causes of material failure in marine engineering, and sulfate-reducing bacteria (SRB) and iron-oxidizing bacteria (IOB) are typical representatives of anaerobic and aerobic microorganisms, respectively. These microorganisms are widely present in marine environments and can form synergistic communities on the surface of metal materials, posing a corrosion threat to them. At the same time, the presence of mixed bacteria may have an effect on cathodic protection, so this study investigates the growth metabolism of mixed SRB and IOB under different cathodic protection potentials in an impressed current cathodic protection (ICCP) system in a marine environment containing SRB and IOB. It also examines the attachment of these microorganisms to the anode and cathode, and the impact on cathodic protection efficiency. The results indicate that in a marine environment containing IOB and SRB, the cathodic protection efficiency of the ICCP system increases with the negative shift of the protection potential. A more positive cathodic protection potential promotes the adhesion of mixed bacteria on the electrode surface and the formation of a biofilm, which reduces cathodic protection efficiency. In contrast, at a cathodic protection potential of −1.05 V (SCE), bacterial growth is inhibited, and a dense crystalline corrosion film primarily composed of Fe₂O₃ and Fe(OH)₃ forms on the cathode surface. This film effectively protects the cathodic metal, significantly mitigating MIC. Full article

The production of fruit brandies is based on distilling fermented fruit juices. Distillation equipment is usually made of copper. In traditional manufacturing, it consists of a boiler (batch) distiller, a boiler (pot), a steam pipe, and a condenser, all of which are made of pure copper. This study determined the corrosion parameters for copper (Cu) and Cu72Zn28 (in wt%) alloy in fermented apricot juice at room temperature. The fermentation process examined in this research utilized natural strains of yeast and bacteria, supplemented by active dry yeast Saccharomyces cerevisiae strains. This research used the following methods: open circuit potential (OCP), linear polarization resistance (LPR), and Tafel extrapolation to identify corrosion parameters. Cu had a 3.8-times-lower value of corrosion current density than brass, and both were within the range of 1–10 μA·cm⁻², with an excellent agreement between LRP and Tafel. This study proved that Cu is an adequate material for the distillation of fruit brandies from a corrosion perspective. Despite this, there are occasional reports of corrosion damage from the field. Significant corrosion impacts can arise, as evidenced by laboratory tests discussed in this paper. In the absence of a highly corrosive environment, this study indicates that, to some extent, microbiologically influenced corrosion (MIC) can influence the degradation of the equipment material. Full article

This study explores the corrosion behavior of pure copper in simulated oilfield-produced water and evaluates the inhibitory effect of cetylpyridinium chloride (CPC) on microbiologically influenced corrosion (MIC). Weight loss tests, potentiodynamic polarization, and pitting analyses revealed that sulfate-reducing bacteria (SRB) activity significantly accelerated corrosion, with the maximum pit depth reaching 7.54 µm in the absence of CPC—approximately 1.83 times greater than under abiotic conditions. The introduction of CPC substantially reduced corrosion rates and pit depths, with maximum pit depths decreasing to 2.97 µm, 1.11 µm, and 1.02 µm at 10, 50, and 80 mg/L CPC, respectively. CPC inhibited SRB biofilm formation, metabolic activity, and corrosion product accumulation, achieving an inhibition efficiency of up to 89% at 80 mg/L. These findings highlight CPC’s dual role as a biocide and a corrosion inhibitor, offering a promising approach to controlling MIC in oilfields and similar industrial environments. Full article

Corrosion costs the Oil & Gas Industry billions of pounds annually, primarily due to environmental factors such as high salinity, temperature fluctuations, and humidity in marine environments. Mobile Offshore Drilling Units (MODUs), especially jack-up rigs, are particularly susceptible to these dangers. This paper examines the impact of cold stacking on aging jack-up rigs and highlights how the absence of an adequate corrosion control system can accelerate structural deterioration. Our findings show that repair costs following cold stacking can far exceed the costs associated with maintaining rigs in a warm-stacked state. Preload tanks are critical areas prone to degradation due to microbiologically influenced corrosion (MIC) and inadequate preservation practices. Furthermore, although high-strength steels are frequently utilized in the construction of jack-up rigs due to their durability, we illustrate that, in the absence of meticulously devised preventative measures, these steels are susceptible to considerable corrosion, resulting in substantial repair expenses and diminished operational lifespans. This study highlights the significance of proactive corrosion control measures in maintaining the long-term structural integrity and cost-effectiveness of offshore drilling units. Full article

Protection against microbiologically influenced corrosion (MIC) is critical for materials used in aquatic environments, as MIC accelerates material degradation and leads to faster structural failure. Copper (Cu) has the potential to substantially improve the MIC resistance in alloys. In this study, high-entropy alloy (HEA) coatings containing Cu were deposited using DC (Direct Current) magnetron sputtering to enhance the corrosion resistance and mechanical properties of various substrates. Two CuCrFeMnNi HEA compositions in the form of bulk alloys and PVD (Physical Vapor Deposition) coatings, with 5% and 10% Cu, were analyzed for their microstructural, mechanical, and anticorrosive characteristics. Deposition parameters were varied to select the optimal values. Microstructural evaluations using SEM-EDS (scanning electron microscopy and energy dispersive X-ray spectroscopy), XRD (X-ray diffraction), and AFM (atomic force microscopy) revealed uniform, dense coatings with good adhesion composed of dendritic and interdendritic BCC (body-centered cubic) and FCC (face centered cubic) structures, respectively. Microhardness tests indicated improved mechanical properties for the samples coated with developed HEAs. The coatings exhibited improved corrosion resistance in NaCl solution, the 10% Cu composition displaying the highest polarization resistance and lowest corrosion rate. These findings suggest that Cu-containing HEA coatings are promising candidates for applications requiring enhanced corrosion protection. Full article

Under natural physiological conditions, the oral cavity is colonized by a diverse range of microorganisms, which inhabit its anatomical structures as well as prosthetic restorations and the supragingival surfaces of implants. The metabolic activity of these microorganisms can contribute to microbiological corrosion, leading to the degradation of metal prosthetic materials. No material used for prosthetic elements is entirely resistant to bacterial adhesion. However, the application of protective coatings, such as Ti(C,N) coatings, on prosthetic surfaces can significantly reduce microorganism adherence. This study aimed to evaluate the influence of carbon and nitrogen content in Ti(C,N) coatings on reducing microorganism adhesion. Tests were conducted on five groups of Ni-Cr alloy specimens, each coated with Ti(C,N) layers containing varying amounts of carbon and nitrogen. The adhesion of E. coli bacteria and C. albicans fungi was assessed under both stationary and dynamic flow conditions. Results demonstrated that all tested coatings significantly reduced microorganism adhesion compared to uncoated Ni-Cr alloy samples. Full article

Microorganisms cause microbiologically influenced corrosion, for the prevention of which bactericide inhibitors are used. The aim of the work was to study in vitro the sensitivity of SRB Desulfovibrio oryzae NUChC SRB1 to different concentrations of dimethyl sulfoxide (DMSO), and evaluate the indicators of the microbial corrosion of steel induced by this bacterium in the presence of the pharmaceutical drugs DMSO and paracetamol. The sensitivity of SRB D. oryzae to 1–100% DMSO (v/v) was studied via the dilution method in Postgate’s “C” liquid medium. The corrosion activity of D. oryzae against steel 3 was investigated under DMSO and paracetamol treatment at a final concentration of 45% (v/v) and 0.2% (w/v), respectively, according to the ability of bacteria to form a biofilm on the surface of the steel samples (via the crystal violet method) and the effect on the corrosion rate (via the gravimetric method). It was revealed that DMSO affected D. oryzae NUChC SRB1 and exhibited bactericidal properties (at a concentration range of 10–100%, v/v) and antibiofilm properties (at a concentration of 45%, v/v). Despite its antibiofilm properties confirmed by the reduction in bacterial biofilm mass, anticorrosion features were not observed in the model 35-day conditions of the microbial corrosion of steel in an anaerobic environment with bacterial sulfate reduction. Paracetamol (0.2%, w/v) did not affect biofilm formation by SRB under these conditions, and significantly contributed to an increase in the rate of the microbial corrosion of steel. The prospect of further research is to assess the effect of DMSO and paracetamol on the indicators of microbial corrosion induced by SRB under the influence of the concentrations of these compounds found in wastewater, to clarify the possible additional causes of damage to the equipment of treatment plants. Further research should also be directed at investigating the antimicrobial properties of complexes of compounds with DMSO, which should be considered as an ecological solution to the problem of microbiologically influenced corrosion prevention. Full article

Concrete, a versatile construction material, faces pervasive deterioration due to microbiologically influenced corrosion (MIC) in various applications, including sewer systems, marine engineering, and buildings. MIC is initiated by microbial activities such as involving sulfate-reducing bacteria (SRB), sulfur-oxidizing bacteria (SOB), etc., producing corrosive substances like sulfuric acid. This process significantly impacts structures, causing economic losses and environmental concerns. Despite over a century of research, MIC remains a debated issue, lacking standardized assessment methods. Microorganisms contribute to concrete degradation through physical and chemical means. In the oil and gas industry, SRB and SOB activities may adversely affect concrete in offshore platforms. MIC challenges also arise in cooling water systems and civil infrastructures, impacting concrete surfaces. Sewer systems experience biogenic corrosion, primarily driven by SRB activities, leading to concrete deterioration. Mitigation traditionally involves the use of biocides and surface coatings, but their long-term effectiveness and environmental impact are questionable. Nowadays, it is important to design more eco-friendly mitigation products. The microbial-influenced carbonate precipitation is one of the green techniques and involves incorporating beneficial bacteria with antibacterial activity into cementitious materials to prevent the growth and the formation of a community that contains species that are pathogenic or may be responsible for MIC. These innovative strategies present promising avenues for addressing MIC challenges and preserving the integrity of concrete structures. This review provides a snapshot of the MIC in various areas and mitigation measures, excluding underlying mechanisms and broader influencing factors. Full article

Microbial corrosion is the deterioration of materials associated with microorganisms in environments, especially in oil- and gas-dominated sectors. It has been widely reported to cause great losses to industrial facilities such as drainage systems, sewage structures, food-processing equipment, and oil and gas facilities. Generally, bacteria, viruses, and other microorganisms are the most important microorganisms associated with microbial corrosion. The destructive nature of these microorganisms differs based on the kind of bacteria involved in the corrosion mechanism. Amongst the microorganisms related to microbial corrosion, sulfate-reducing bacteria (SRB) is reported to be the most common harmful bacteria. The detailed mechanistic explanations relating to the corrosion of pipelines by sulfate-reducing bacteria are discussed. The mechanism of microbial corrosion in pipelines showing the formation of pitting corrosion and cathodic depolarization is also reported. The current review provides theoretical information for the control and protection of pipelines caused by microbial corrosion and how new eco-friendly protection methods could be explored. Full article

The development of pitting corrosion on L245 carbon steel in a culture medium solution containing sulfate-reducing bacteria (SRB) was investigated. The results showed that the occurrence of corrosion in L245 carbon steel is closely linked to the evolution of biofilm and product film. As the test duration extended, overall corrosion was inhibited. Simultaneously, bacteria beneath the film layer promoted the generation and development of pitting corrosion, and the aggregation of bacteria (colonies) led to the aggregation of pitting corrosion. Full article

Objective Sulfate-reducing bacteria (SRB) pose a threat to the safe operation of shale-gas-gathering pipelines. Therefore, it is essential to explore the role played by SRB in dedicated pipelines. Methods In this work, the corrosion behavior of SRB was investigated by organic carbon starvation immersion experiments combined with cell number monitoring, corrosion weight loss recordings, morphology and profile observations and electrochemical measurements. Results In experiments with sodium lactate content ranging from 0–3500 ppm, the corrosion rate and pitting depth were the highest at 350 ppm. Conclusions The results indicated that the reduction in carbon sources leads to bacterial starvation, which directly obtains electrons from metals and exacerbates corrosion. It is not appropriate to use the content of bacteria to determine the strength of bacterial corrosion. Full article