Two experiments were conducted during 2006-2007 in Complete Randomized Design （CRD） to test the biological activity of Pseudomonas bacteria as biocides to protect sesame crop from some fungi and to evaluate its eff...Two experiments were conducted during 2006-2007 in Complete Randomized Design （CRD） to test the biological activity of Pseudomonas bacteria as biocides to protect sesame crop from some fungi and to evaluate its efficiency as plant growth promoting First experiment investigated the effects of Pseudomonas putida2 and Pseudomonas fluorescens3 on germination and seedlings growth of sesame crop against Pythium, Alternaria and Fusarium under plastic house conditions. Second experiment conducted in large pots to investigate the effects of the two bacterial isolates on some morphological, productive and physiological characters of sesame plants against same fungi under normal conditions. Results showed very low germination and slowly seedlings growth in Pythium, Fusarium and Alternaria treatments respectively, but adding bacterial vaccine of Pseudomonas putida2 and Pseudomonas fluorescens3 as a Biocide to fungi treatments, increased the germination percent and seedlings growth of sesame crop significantly, 20 days after planting compared with control treatment. In the second experiment, control treatment scored germination by 52%, while vaccines of Pseudornonas putida2 and Pseudomonas fluorescence3 treatments increased germination percentage in Fusarium, Pythium and Alternaria treatments significantly in average more than 71%. Both isolates increased significantly Leaf number per plant, leaf area per plant, height of plant, branches number per plant, total dry weight of shoot per plant and chlorophyll content compared with other and control treatments. Similar significant effect for both isolates was recorded in seeds number per pod per plant, total weight of 1,000 seeds per plant and pods number per plant and percentage of N, P, K in total dry weight of shoot per plant and oil percentage in seeds per plant compared with other and control treatments. P. putida2 increased oil percentage in seeds by 43.3, 48.0 and 45.0% respectively while with P. fluorescens3 increased to 42.7, 44.0 and 43.7% respectively compared with control treatment （27.7%）. In general Pseudomonas putida2 increased most of growth characters much higher than Pseudomonas fluorescens3, it may related to siderophores compound and genetic factors.展开更多
The widespread and indiscriminate use of biocides poses significant threats to global health,socioeconomic development,and environmental sustainability by accelerating antibiotic resistance.Bacterial resistance develo...The widespread and indiscriminate use of biocides poses significant threats to global health,socioeconomic development,and environmental sustainability by accelerating antibiotic resistance.Bacterial resistance development is highly complex and influenced significantly by environmental factors.Increased biocide usage in households,agriculture,livestock farming,industrial settings,and hospitals produces persistent chemical residues that pollute soil and aquatic environments.Such contaminants contribute to the selection and proliferation of resistant bacteria and antimicrobial resistance genes(ARGs),facilitating their dissemination among humans,animals,and ecosystems.In this review,we conduct a critical assessment of four significant issues pertaining to this topic.Specifically,(i)the role of biocides in exerting selective pressure within the environmental resistome,thereby promoting the proliferation of resistant microbial populations and contributing to the global spread of antimicrobial resistance genes(ARGs);(ii)the role of biocides in triggering transient phenotypic adaptations in bacteria,including efflux pump overexpression,membrane alterations,and reduced porin expression,which often result in cross-resistance to multiple antibiotics;(iii)the capacity of biocides to disrupt bacteria and make the genetic content accessible,releasing DNA into the environment that remains intact under certain conditions,facilitating horizontal gene transfer and the spread of resistance determinants;(iv)the capacity of biocides to disrupt bacterial cells,releasing intact DNA into the environment and enhancing horizontal gene transfer of resistance determinants;and(iv)the selective interactions between biocides and bacterial biofilms in the environment,strengthening biofilm cohesion,inducing resistance mechanisms,and creating reservoirs for resistant microorganisms and ARG dissemination.Collectively,this review highlights the critical environmental and public health implications of biocide use,emphasizing an urgent need for strategic interventions to mitigate their role in antibiotic resistance proliferation.展开更多
Antimicrobial substances are substances that have the ability to kill or slow down the growth of microorganisms such as bacteria,algae and fungi.Exposure of microorganisms to low concentrations of antimicrobial substa...Antimicrobial substances are substances that have the ability to kill or slow down the growth of microorganisms such as bacteria,algae and fungi.Exposure of microorganisms to low concentrations of antimicrobial substances may lead to the development of antimicrobial resistance.To protect human health and the environment and to limit resistance,the risks for the release of these substances into the environment should be minimized from all sources.Under the current EU legal framework,some specific uses of antimicrobial substances are strictly regulated whereas others are not.When antimicrobial substances are used as active substances in biocidal products,such as disinfectants,they are regulated by Biocidal Products Regulation.When the same substances are used as preservatives in cosmetic products they fall under Cosmetic Products Regulation.In this paper,we investigated how the regulation of antimicrobial substances differ when used in biocidal products compared to cosmetic products.This was achieved by performing a systematic comparison using document analysis with focus on aims,scope,information requirements,and risk assessment procedures for biocidal active substances and cosmetic preservatives.One of the main differences identified is that no environmental data or environmental risk assessment are required for approval of cosmetic preservatives.In contrast,environmental data and risk assessment for both the active substances and one representative product would be required for the approval of the same substance if used as a biocidal active substance.This means first that a substance not approved for use in biocidal products due to its hazardous environmental properties can still be approved as a cosmetic preservative.And second,the environmental release of antimicrobial substances from cosmetic products remains unassessed and uncontrolled,despite the obvious risks of cosmetic ingredients being emitted into the environment via wastewater.From this,we recommend that an environmental risk assessment is added to the requirements for market approval of cosmetic preservatives to achieve the aim of a high level of protection for the environment as set by several EU regulations.This would be in line with the“one substance e one assessment”approach proposed by the European Commission.While the details of“one substance e one assessment”approach are not decided,it is believed to contribute to more coordinated and transparent chemical safety assessments and enhance interlinking between the regulations.展开更多
We have investigated the mode of action of synthetic biocides,(2-(thiocyanomethylthio)benzothiazole(TCMTB),dichlorophen,(commonly used in leather industry for preservation)and natural biocides,oregano and eucalyptus o...We have investigated the mode of action of synthetic biocides,(2-(thiocyanomethylthio)benzothiazole(TCMTB),dichlorophen,(commonly used in leather industry for preservation)and natural biocides,oregano and eucalyptus oils,on Aeromonas hydrophila using Raman spectroscopy in collaboration with multivariate analysis and 2D correlation spectroscopy to evaluate whether Raman spectra acquired contained valuable information to study the action of biocides on bacterial cells.The growth of A.hydrophila in clear and outer edge zone of inhibition differ in their reaction with different biocides,which allows us to highlight the differences as a characteristic of two kinds of bacteria.Such classification helps identify oregano oil as the most effective biocide by altering clear and outer edge zone of bacteria.Standard disk diffusion assay method was used for screening biocide bacteria interactions and later analysed by Raman spectroscopy.The paper also presents the introduction of TCMTB and oregano oil into leather processing stages to examine and determine the antimicrobial effect as an application to real-world setting.Therefore,we conclude that Raman spectroscopy with appropriate computational tools constitutes a powerful approach for screening biocides,which provide solutions to all the industries using biocides including leather industry,considering the potentially harmful effect of biocides to humans and the environment.展开更多
This study focused on the production of polypropylene(PP)/silver(Ag)composites via additive manufacturing.This study aimed to enhance the quality of medical-grade PP in material extrusion(MEX)three-dimensional printin...This study focused on the production of polypropylene(PP)/silver(Ag)composites via additive manufacturing.This study aimed to enhance the quality of medical-grade PP in material extrusion(MEX)three-dimensional printing(3DP)by improving its mechanical properties while simultaneously adding antibacterial properties.The latter can find extremely important and versatile properties that are applicable in defense and security domains.PP/Ag nanocomposites were prepared using a novel method based on a reaction occurring while mixing appropriate quantities of the starting polymers and additives,namely polyvinylpyrrolidone(PVP)as the matrix material and silver nitrate(AgNO_(3))as the filler.This process produced three-dimensional(3D)printed filaments,which were then used to create specimens for a series of standardized tests.It was found that the mechanical properties of the nanocomposites were enhanced in relation to pristine PP,especially for the PP matrix with various loadings of AgNO_(3)and PVP,such as 5.0 wt%and 2.5 wt%,respectively.The voids,inclusions,and actual-to-nominal dimensions also showed improved results.The 3DP specimens exhibited a more effective biocidal performance against Staphylococcus aureus than Escherichia coli,which developed an inhibition zone only in the case of PP with filler loading percentages of AgNO_(3)and PVP at 10.0 wt%and 5.0 wt%,respectively Compounds possessing such properties can be beneficial for various applications requiring increased mechanical properties and biocidal capabilities,such as in the Defence or medical industries.展开更多
Organic biocides as timber preservatives have aroused more and more attention,because metal salts especially arsenic,chrome and so on, have been suspected to be poisonous to the soil and aquatic animals,as well as the...Organic biocides as timber preservatives have aroused more and more attention,because metal salts especially arsenic,chrome and so on, have been suspected to be poisonous to the soil and aquatic animals,as well as the disposal of preserved timber wastes.Therefore,a number of effective organic biocides have been selected to prevent wood or bamboo from decay,mildew, stain and so on.Most of these products have entered into the market.With people’s increasing awareness of the environmental protection,organic biocides will eventually play important roles in timber preservation in the future.This paper summarized the studies on application of organic biocides as wood or bamboo preservatives,including resistant mechanisms,commonly applied types and effects against wood or bamboo fungi,approaches to detecting the amount of organic biocides in timber and their influences on the environment.Based on the discussion above,the authors predicted the developing prospect of organic biocides in timber preservation.展开更多
The exposure patterns of pest control and disinfection workers have changed after the coronavirus disease 2019(COVID-19)outbreak,but the health risks of chemical exposure have not been assessed.We identified these wor...The exposure patterns of pest control and disinfection workers have changed after the coronavirus disease 2019(COVID-19)outbreak,but the health risks of chemical exposure have not been assessed.We identified these workers’chemical exposure patterns and risks before and after the COVID-19 outbreak.We used data conducted between 2018(pre-pandemic)and 2021(post-pandemic)from three-year cross-sectional surveys on pest control and disinfection workers.Inhalation and dermal exposure concentrations were estimated using equations based on a biocidal product risk assessment model from the Korean National Institute of Environmental Research.The non-carcinogenic and carcinogenic risks of chemicals were calculated using the United States Environmental Protection Agency risk assessment model.We found that the annual work frequency(50^(th)percentile)of foggers using disinfectants increased the most among all the work types,from 140 uses/year to 176 uses/year after the COVID-19 outbreak.Moreover,all chemicals’non-carcinogenic and carcinogenic risks increased regardless of exposure routes.In the worst scenario(95^(th)percentile),the margin of exposure for citric acid,benzethonium chloride,benzyl-C12-16-alkyldimethyl chlorides,and sodium chlorite of inhalation exposure,and isopropyl alcohol and benzyl-C12-16-alkyldimethyl chlorides of dermal exposure were acceptable(>100)before the COVID-19outbreak but became unacceptable(<100)after the COVID-19 outbreak.Carcinogenic risks of dichlorvos from inhalation and dermal exposure were above acceptable levels(>10^(-6))before and after the COVID-19 outbreak but comparatively high after the COVID-19 outbreak.Additionally,significantly more workers experienced health symptoms after the COVID-19outbreak(p<0.05),with the most common being muscle lethargy(31%),skin/face stinging(28.7%),and breath shortness/neck pain(24.1%).展开更多
Attachment of bacteria and subsequent formation of biofilms on material surfaces lead to serious consequences including infection,contamination and biofouling,posing a prominent threat to human health and causing prob...Attachment of bacteria and subsequent formation of biofilms on material surfaces lead to serious consequences including infection,contamination and biofouling,posing a prominent threat to human health and causing problems in many industries.Therefore,it is highly desirable to endow the surfaces with antibacterial properties.Traditional antibacterial surfaces are designed via either bacteria-resisting strategy to prevent the initial adhesion of bacteria or bacteria-killing strategy to eradicate any bacteria that attach to the surface.However,these single-function surfaces have their inherent shortcomings and cannot realize long-term efficacy against bacteria.In recent years,various dual-function antibacterial surfaces with both bacteria-resisting and bacteria-killing properties together have been developed,showing better performance for combating surface-attached bacteria and preventing formation of biofilms.In this review,we summarize the recent development of these dual-function antibacterial surfaces.We focus on the design principles and fabrication strategies of such surfaces and highlight the representative examples,which are categorized specifically into two types according to the anti-adhesive and bactericidal properties are simultaneous or switchable.A brief perspective is finally presented on current challenges and future research directions.展开更多
Nanoparticles have been used as diagnostic and therapeutic agents in the human medical field for quite some time, though their application in veterinary medicine and animal production is still relatively new. Recently...Nanoparticles have been used as diagnostic and therapeutic agents in the human medical field for quite some time, though their application in veterinary medicine and animal production is still relatively new. Recently,production demands on the livestock industry have been centered around the use of antibiotics as growth promoters due to growing concern over microbial antibiotic resistance. With many countries reporting increased incidences of antibiotic-resistant bacteria, laws and regulations are being updated to end in-feed antibiotic use in the animal production industry. This sets the need for suitable alternatives to be established for inclusion in feed.Many reports have shown evidence that nanoparticles may be good candidates for animal growth promotion and antimicrobials. The current status and advancements of nanotechnological applications in animal production will be the focus of this review and the emerging roles of nanoparticles for nutrient delivery, biocidal agents, and tools in veterinary medicine and reproduction will be discussed. Additionally, influences on meat, egg, and milk quality will be reviewed.展开更多
The use of seawater for industrial cooling is a vital technology that poses some of the most profound environmental impact on the water quality in the Arabian Gulf. Biocide (chlorine) is added to the seawater to contr...The use of seawater for industrial cooling is a vital technology that poses some of the most profound environmental impact on the water quality in the Arabian Gulf. Biocide (chlorine) is added to the seawater to control biofouling of the cooling system. This added chlorine reacts with bromide and other chemicals naturally exist in the water to form a wide range of oxidants. Regrettably, reactions between the residual oxidants and natural organic matter in the water lead to formation of toxic halogenated organic compounds that have detrimental effects on the environment when they are discharged into the Gulf. This paper describes the formation of trihalomethanes (THMs) in seawater cooling systems. Results of kinetic experiments have shown that concentrations of THMs increased rapidly with time during the first half hour. Chlorination of seawater has shown significant increase in total THMs (TTHMs) and in bromoform concentrations. Rapid decrease of UV absorbance at 254 nm was also observed during seawater chlorination which is indicative of natural organic matter degradation into small organic molecules including THMs and other by-products. The increase in chlorine dose was accompanied with an increase in TTHMs and bromoform concentrations. Linear relationships between total chlorine concentration and both final TTHMs and bromoform concentrations were established. First order exponential decay and exponential associate functions were developed to correlate chlorine dose with formed THMs.展开更多
Background: Annonaceous acetogenins enclose a large number of biological activities, among which the insecticidal stands out. Methods: We report herein the biocide effects of natural acetogenins from Annona squamosa, ...Background: Annonaceous acetogenins enclose a large number of biological activities, among which the insecticidal stands out. Methods: We report herein the biocide effects of natural acetogenins from Annona squamosa, A.?muricata and A. montana seeds: annonacin, cis-annonacin, cis-annonacin-10- one, asimicin, rolliniastatin-2, cherimolin-1, cherimolin-2, almuñequin, and two β-OH acetogenins: laherradurin and itrabin on Spodoptera frugiperda Smith (Lepidoptera: Noctuidae). Also, some acetylated and methoxy methylated ACG derivatives were synthesized and evaluated: annonacin (3 OAc), annonacin (4 OAc), asimicin (3 OAc), rolliniastatin-2 (3 OAc), rolliniastatin-2 (MOM), laherradurin (3 OAc) and itrabin (3 OAc). Results: The natural acetogenin rolliniastatin-2 (100 μg·g-1 of diet) produced the most important toxic action causing 100% mortality of early instar larvae. Derivatization of ACG yielded compounds that produced nutritional alterations. The incorporation of rolliniastatin-2 (3 OAc) and rolliniastatin-2 (3 MOM) (100 μg·g-1) into the artificial diet of Spodoptera frugiperdadisplayed the strongest antifeedant effects causing marked decreasings in larval growth and adult lethal malformations. Conclusion: Natural acetogenins are promising metabolites for insect control. Derivatization of these compounds reduces their toxicity to early instar larvae.展开更多
The science and technology interact with the art in several ways. Biotechnological coupled with analytical approaches can play an important role in protecting and preserving cultural heritage for future generations. M...The science and technology interact with the art in several ways. Biotechnological coupled with analytical approaches can play an important role in protecting and preserving cultural heritage for future generations. Many microorganisms influenced by environmental conditions are the main responsible for biological contamination in built heritage. Biocides based on chemical compounds have been used to mitigate this problem. Thus, it is vitally important to develop proper remediation actions based on environmentally innocuous alternative. Bacillus specie is emerging as an optimistic alternative for built heritage treatment due to their capacity to produce secondary metabolites with antagonistic activities against many fungal pathogens. Therefore, the intent of this work was to access a rapid evaluation of antifungal potential of bioactive metabolites produced by Bacillus strains and simultaneously their characterization using spectroscopic (NMR) and chromatographic techniques (LC-ESI-MS). The high antifungal activity obtained for Bacillus sp. active compounds produced in this study confirms the great potential to suppress biodeteriogenic fungi growth on historical artworks. Additionally, the proposed methodology allowed to access bioactive metabolites produced without need of the laborious total previous isolation and could be used as a viable alternative to be employed for screening and production of new green biocides.展开更多
Antimicrobial resistance(AMR)poses a significant threat to public health and is increasingly recognized within the“One Health”framework,which emphasizes the interconnectedness of human,animal,and environmental healt...Antimicrobial resistance(AMR)poses a significant threat to public health and is increasingly recognized within the“One Health”framework,which emphasizes the interconnectedness of human,animal,and environmental health.While extensive research has focused on regulating antibiotic use across healthcare and other sectors,the impact of intensive biocide use on AMR development,particularly in seawater-cooled systems,remains underexplored.In this study,we report the isolation and characterization of a multidrug-resistant Klebsiella quasipneumoniae strain from the cooling water system of a coastal power plant,where continuous chlorination at 0.2 ppm is employed for biofouling control.The isolated strain displayed broad-spectrum resistance to multiple biocides and antibiotics.Interestingly,the strain shown enhances biofilm formation in response to biocides and antibiotics,thereby compounding its resistance profile.Efflux assays with ethidium bromide(EtBr)and whole-genome sequencing revealed that efflux pumps are central to the resistance mechanisms.Additionally,the presence ofβ-lactamase(OKP-A)and FosA genes confers resistance to theβ-lactam and epoxide classes of antibiotics.The strain was found to be salt-tolerant and preferred to grow at normal salinity,indicating a non-marine origin of this isolate.These findings highlight the prevalence of biocide and antibiotic-resistant pathogens in marine cooling water systems that primarily rely on biocides for biofouling control.In line with One Health principles,our research advocates for a reassessment of biocide practices in marine cooling water systems and the implementation of proactive measures to mitigate the spread of antimicrobial resistance(AMR).展开更多
Seawater desalination is one of the major industrial activities along the coastline of Kuwait that poses profound environmental impact on the quality of seawater.This study focuses on investigating the potential conta...Seawater desalination is one of the major industrial activities along the coastline of Kuwait that poses profound environmental impact on the quality of seawater.This study focuses on investigating the potential contamination of biocides,volatile organic hydrocarbons(VOCs)and other halogenated hydrocarbons discharged from Az-Zour desalination plant.Chemical contamination by residual chlorine(RC)and some VOCs was detected in effluents from inside and at the vicinity of the plant.RC ranged between 0.15 and 0.49 mg/L while bromoform(CHBr3)was the highest of all the VOCs detected and ranged between 0.22 and 3.30μg/L.Benzinoides(benzene,toluene,xylene and ethylbenzene)were also detected at 0.1μg/L and 0.25μg/L.The levels of RC as measured in the vicinity of the Az-Zour plant are below the limit set up by Kuwait EPA.However,it still poses effects to the nearby aquatic life and therefore,it is important to lower the concentration of RC in the discharge effluent.展开更多
Annonaceous acetogenins enclose a large number of biological activities, among which the insecticidal stands out. <em>Spodoptera frugiperda</em> is a pest that affects corn crops among others and has a gre...Annonaceous acetogenins enclose a large number of biological activities, among which the insecticidal stands out. <em>Spodoptera frugiperda</em> is a pest that affects corn crops among others and has a great capacity to develop resistance to traditional insecticides, which represents sufficient reasons for the search for new alternatives for their control. The objective of this study was to determine the appropriate concentration and screening new natural insecticides against second instar larvae of <em>S. frugiperda</em>, under glasshouse conditions on <em>Zea mays</em> L. Natural products such as annonaceous acetogenins and some acetylated and methoxy methylated ACG derivatives and the commercial product Lambda-cyhalotrin (LC) were evaluated. The percent mortalities of <em>S. frugiperda </em>larvae in glasshouse conditions were recorded after 24, 48 and 72 h of treatment application. The results showed that the acetogenins tested were significantly (P < 0.05) different in relation to pest mortality than untreated check. After 72 h of treatment application the highest percent mortalities were obtained with the mixture of two natural products, rolliniastatin-2 (<strong>5</strong>) (100 μg/mL) + squamocin (<strong>6</strong>) (100 μg/mL) + LC (50 μg/mL) that proved the most effective and gave (100%), while rolliniastatin-2 (<strong>5</strong>) at 100 μg/mL alone, gave lowest percent mortality (65%), followed by squamocin (<strong>6</strong>) at 100 μg/mL (55%) and LC at 50 μg/mL (30%). The acetylated and methoxy methylated ACGs derivatives caused very low mortality (25% - 35%). It is recommended the mixture as a management option of <em>S. frugiperda</em> as a component of integrated pest management. The results allow us to infer that the addition of natural ACGs synergizes the insecticidal activity of the commercial product. Finding a new ecological alternative for insect control.展开更多
Emulsive polymerization of mono- and dy(meth)acrylates of butandiol, decid(meth)acrylate, methyl-α-alkilacrylates with industrial acrylic monomers—butylacrylate, methylacrylate, methacrylic acid, methyl(meth)acrylat...Emulsive polymerization of mono- and dy(meth)acrylates of butandiol, decid(meth)acrylate, methyl-α-alkilacrylates with industrial acrylic monomers—butylacrylate, methylacrylate, methacrylic acid, methyl(meth)acrylate has been investigated. Structurization of copolymers using dy(meth)acrylates of butandiol, braking of emulsive polymerization using water insoluble biocides, dy(meth)acrylates of butandiol and methyl-α-alkilacrylates have been determined. The mechanism of emulsive polymerization of (meth)acrylic monomers using methyl-α-alkilacrylates has been investigated.展开更多
The corrosion damage of 20 SiMn steel by sulphate-reducing bacteria(SRB)and the mitigation effect of organic silicon quaternary ammonium salt(OSA)were studied in sterilized mild alkaline simulated concrete pore soluti...The corrosion damage of 20 SiMn steel by sulphate-reducing bacteria(SRB)and the mitigation effect of organic silicon quaternary ammonium salt(OSA)were studied in sterilized mild alkaline simulated concrete pore solution(STR)with different additions of SRB and OSA at pH 9.35 for 28 days.Uniform corrosion occurs in STR medium while slight localized corrosion is observed in STR+OSA medium,and localized pitting corrosion occurs in STR+SRB and STR+SRB+OSA media.The largest pit depth reduces from 36.70μm in STR+SRB medium to 3.31μm in STR+SRB+OSA medium due to the mitigation effect of OSA.The corrosion rate reflected by weight loss and electrochemical impedance spectroscopy(EIS)results presents the order of STR<STR+OSA<STR+SRB+OSA<STR+SRB,which also proves that the presence of SRB can accelerate corrosion in a carbonated medium.However,OSA as an efficient bacteriostatic agent can reduce the excessive growth of SRB and thus reduce corrosion.展开更多
Tetrakis hydroxymethyl phosphonium sulfate(THPS) was enhanced by a 14-mer Peptide A, with its core12-mer sequence mimicking part of Equinatoxin II protein, in the mitigation of sulfate reducing Desulfovibrio ferrophil...Tetrakis hydroxymethyl phosphonium sulfate(THPS) was enhanced by a 14-mer Peptide A, with its core12-mer sequence mimicking part of Equinatoxin II protein, in the mitigation of sulfate reducing Desulfovibrio ferrophilus MIC(microbiologically influenced corrosion) of X80 carbon steel. Results proved that50 ppm(w/w) THPS was sufficient to mitigate the D. ferrophilus biofilm, and its very agressive MIC(19.7mg/cm^(2) in 7 days or 1.31 mm/a), but not 20 ppm THPS. To achieve effective mitigation at a low dosage of THPS, biofilm-dispersing Peptide A was added to 20 ppm THPS in the culture medium. Sessile cell counts were reduced by 2-log and 4-log after enhancement by 10 ppb and 100 ppb Peptide A, respectively. Enhancement efficiency(further reduction in corrosion rate) reached 69% for 10 ppb Peptide A and 83% for100 ppb Peptide A compared with 20 ppm THPS alone treatment, indicating that Peptide A was a good biocide enhancer for THPS.展开更多
In the oil and gas industry,microbiologically influenced corrosion(MIC) is a major threat to hydrotest,a procedure which is required to certify whether a pipeline can be commissioned.Seawater is frequently used as a h...In the oil and gas industry,microbiologically influenced corrosion(MIC) is a major threat to hydrotest,a procedure which is required to certify whether a pipeline can be commissioned.Seawater is frequently used as a hydrotest fluid.In this bio film prevention lab study,an oilfield biofilm consortium was grown in an enriched artificial seawater anaerobically at 37℃ for 60 days.The combination of 100 ppm(w/w) 2,2-dibromo-3-nitrilopropionamide(DBNPA)+100 nM(180 ppb) Peptide A(a biofilm dispersal agent) led to extra SRB(sulfate reducing bacteria),APB(acid producing bacteria) and GHB(general heterotrophic bacteria) sessile cell count reductions of 0.9-log,0.8-log and 0.6-log,respectively,compared with the outcome obtained by using 100 ppm DBNPA only.The Peptide Aenhancement also led to extra reductions of 44 % in weight loss,43 % in maximum pit depth,and 54 % in corrosion current density.展开更多
文摘Two experiments were conducted during 2006-2007 in Complete Randomized Design （CRD） to test the biological activity of Pseudomonas bacteria as biocides to protect sesame crop from some fungi and to evaluate its efficiency as plant growth promoting First experiment investigated the effects of Pseudomonas putida2 and Pseudomonas fluorescens3 on germination and seedlings growth of sesame crop against Pythium, Alternaria and Fusarium under plastic house conditions. Second experiment conducted in large pots to investigate the effects of the two bacterial isolates on some morphological, productive and physiological characters of sesame plants against same fungi under normal conditions. Results showed very low germination and slowly seedlings growth in Pythium, Fusarium and Alternaria treatments respectively, but adding bacterial vaccine of Pseudomonas putida2 and Pseudomonas fluorescens3 as a Biocide to fungi treatments, increased the germination percent and seedlings growth of sesame crop significantly, 20 days after planting compared with control treatment. In the second experiment, control treatment scored germination by 52%, while vaccines of Pseudornonas putida2 and Pseudomonas fluorescence3 treatments increased germination percentage in Fusarium, Pythium and Alternaria treatments significantly in average more than 71%. Both isolates increased significantly Leaf number per plant, leaf area per plant, height of plant, branches number per plant, total dry weight of shoot per plant and chlorophyll content compared with other and control treatments. Similar significant effect for both isolates was recorded in seeds number per pod per plant, total weight of 1,000 seeds per plant and pods number per plant and percentage of N, P, K in total dry weight of shoot per plant and oil percentage in seeds per plant compared with other and control treatments. P. putida2 increased oil percentage in seeds by 43.3, 48.0 and 45.0% respectively while with P. fluorescens3 increased to 42.7, 44.0 and 43.7% respectively compared with control treatment （27.7%）. In general Pseudomonas putida2 increased most of growth characters much higher than Pseudomonas fluorescens3, it may related to siderophores compound and genetic factors.
基金supported by national funds through FCT/MCTES(PIDDAC):LEPABE,UIDB/00511/2020(DOI:10.54499/UIDB/00511/2020)UIDP/00511/2020(DOI:10.54499/UIDP/00511/2020)+2 种基金ALiCE,LA/P/0045/2020(DOI:10.54499/LA/P/0045/2020)by Project Innov Anti Biofilm(ref.101157363)financed by European Commission(Horizon-Widera 2023-Acess-02/Horizon-CSA)Mariana Sousa's PhD scholarship(2023.00337.BD)is provided by The Foundation for Science and Technology(FCT).
文摘The widespread and indiscriminate use of biocides poses significant threats to global health,socioeconomic development,and environmental sustainability by accelerating antibiotic resistance.Bacterial resistance development is highly complex and influenced significantly by environmental factors.Increased biocide usage in households,agriculture,livestock farming,industrial settings,and hospitals produces persistent chemical residues that pollute soil and aquatic environments.Such contaminants contribute to the selection and proliferation of resistant bacteria and antimicrobial resistance genes(ARGs),facilitating their dissemination among humans,animals,and ecosystems.In this review,we conduct a critical assessment of four significant issues pertaining to this topic.Specifically,(i)the role of biocides in exerting selective pressure within the environmental resistome,thereby promoting the proliferation of resistant microbial populations and contributing to the global spread of antimicrobial resistance genes(ARGs);(ii)the role of biocides in triggering transient phenotypic adaptations in bacteria,including efflux pump overexpression,membrane alterations,and reduced porin expression,which often result in cross-resistance to multiple antibiotics;(iii)the capacity of biocides to disrupt bacteria and make the genetic content accessible,releasing DNA into the environment that remains intact under certain conditions,facilitating horizontal gene transfer and the spread of resistance determinants;(iv)the capacity of biocides to disrupt bacterial cells,releasing intact DNA into the environment and enhancing horizontal gene transfer of resistance determinants;and(iv)the selective interactions between biocides and bacterial biofilms in the environment,strengthening biofilm cohesion,inducing resistance mechanisms,and creating reservoirs for resistant microorganisms and ARG dissemination.Collectively,this review highlights the critical environmental and public health implications of biocide use,emphasizing an urgent need for strategic interventions to mitigate their role in antibiotic resistance proliferation.
文摘Antimicrobial substances are substances that have the ability to kill or slow down the growth of microorganisms such as bacteria,algae and fungi.Exposure of microorganisms to low concentrations of antimicrobial substances may lead to the development of antimicrobial resistance.To protect human health and the environment and to limit resistance,the risks for the release of these substances into the environment should be minimized from all sources.Under the current EU legal framework,some specific uses of antimicrobial substances are strictly regulated whereas others are not.When antimicrobial substances are used as active substances in biocidal products,such as disinfectants,they are regulated by Biocidal Products Regulation.When the same substances are used as preservatives in cosmetic products they fall under Cosmetic Products Regulation.In this paper,we investigated how the regulation of antimicrobial substances differ when used in biocidal products compared to cosmetic products.This was achieved by performing a systematic comparison using document analysis with focus on aims,scope,information requirements,and risk assessment procedures for biocidal active substances and cosmetic preservatives.One of the main differences identified is that no environmental data or environmental risk assessment are required for approval of cosmetic preservatives.In contrast,environmental data and risk assessment for both the active substances and one representative product would be required for the approval of the same substance if used as a biocidal active substance.This means first that a substance not approved for use in biocidal products due to its hazardous environmental properties can still be approved as a cosmetic preservative.And second,the environmental release of antimicrobial substances from cosmetic products remains unassessed and uncontrolled,despite the obvious risks of cosmetic ingredients being emitted into the environment via wastewater.From this,we recommend that an environmental risk assessment is added to the requirements for market approval of cosmetic preservatives to achieve the aim of a high level of protection for the environment as set by several EU regulations.This would be in line with the“one substance e one assessment”approach proposed by the European Commission.While the details of“one substance e one assessment”approach are not decided,it is believed to contribute to more coordinated and transparent chemical safety assessments and enhance interlinking between the regulations.
基金The research is funded by the Ministry of Business,Innovation and Employment(MBIE)grant number LSRX1801.
文摘We have investigated the mode of action of synthetic biocides,(2-(thiocyanomethylthio)benzothiazole(TCMTB),dichlorophen,(commonly used in leather industry for preservation)and natural biocides,oregano and eucalyptus oils,on Aeromonas hydrophila using Raman spectroscopy in collaboration with multivariate analysis and 2D correlation spectroscopy to evaluate whether Raman spectra acquired contained valuable information to study the action of biocides on bacterial cells.The growth of A.hydrophila in clear and outer edge zone of inhibition differ in their reaction with different biocides,which allows us to highlight the differences as a characteristic of two kinds of bacteria.Such classification helps identify oregano oil as the most effective biocide by altering clear and outer edge zone of bacteria.Standard disk diffusion assay method was used for screening biocide bacteria interactions and later analysed by Raman spectroscopy.The paper also presents the introduction of TCMTB and oregano oil into leather processing stages to examine and determine the antimicrobial effect as an application to real-world setting.Therefore,we conclude that Raman spectroscopy with appropriate computational tools constitutes a powerful approach for screening biocides,which provide solutions to all the industries using biocides including leather industry,considering the potentially harmful effect of biocides to humans and the environment.
文摘This study focused on the production of polypropylene(PP)/silver(Ag)composites via additive manufacturing.This study aimed to enhance the quality of medical-grade PP in material extrusion(MEX)three-dimensional printing(3DP)by improving its mechanical properties while simultaneously adding antibacterial properties.The latter can find extremely important and versatile properties that are applicable in defense and security domains.PP/Ag nanocomposites were prepared using a novel method based on a reaction occurring while mixing appropriate quantities of the starting polymers and additives,namely polyvinylpyrrolidone(PVP)as the matrix material and silver nitrate(AgNO_(3))as the filler.This process produced three-dimensional(3D)printed filaments,which were then used to create specimens for a series of standardized tests.It was found that the mechanical properties of the nanocomposites were enhanced in relation to pristine PP,especially for the PP matrix with various loadings of AgNO_(3)and PVP,such as 5.0 wt%and 2.5 wt%,respectively.The voids,inclusions,and actual-to-nominal dimensions also showed improved results.The 3DP specimens exhibited a more effective biocidal performance against Staphylococcus aureus than Escherichia coli,which developed an inhibition zone only in the case of PP with filler loading percentages of AgNO_(3)and PVP at 10.0 wt%and 5.0 wt%,respectively Compounds possessing such properties can be beneficial for various applications requiring increased mechanical properties and biocidal capabilities,such as in the Defence or medical industries.
文摘Organic biocides as timber preservatives have aroused more and more attention,because metal salts especially arsenic,chrome and so on, have been suspected to be poisonous to the soil and aquatic animals,as well as the disposal of preserved timber wastes.Therefore,a number of effective organic biocides have been selected to prevent wood or bamboo from decay,mildew, stain and so on.Most of these products have entered into the market.With people’s increasing awareness of the environmental protection,organic biocides will eventually play important roles in timber preservation in the future.This paper summarized the studies on application of organic biocides as wood or bamboo preservatives,including resistant mechanisms,commonly applied types and effects against wood or bamboo fungi,approaches to detecting the amount of organic biocides in timber and their influences on the environment.Based on the discussion above,the authors predicted the developing prospect of organic biocides in timber preservation.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.NRF-2021R1F1A1063967)。
文摘The exposure patterns of pest control and disinfection workers have changed after the coronavirus disease 2019(COVID-19)outbreak,but the health risks of chemical exposure have not been assessed.We identified these workers’chemical exposure patterns and risks before and after the COVID-19 outbreak.We used data conducted between 2018(pre-pandemic)and 2021(post-pandemic)from three-year cross-sectional surveys on pest control and disinfection workers.Inhalation and dermal exposure concentrations were estimated using equations based on a biocidal product risk assessment model from the Korean National Institute of Environmental Research.The non-carcinogenic and carcinogenic risks of chemicals were calculated using the United States Environmental Protection Agency risk assessment model.We found that the annual work frequency(50^(th)percentile)of foggers using disinfectants increased the most among all the work types,from 140 uses/year to 176 uses/year after the COVID-19 outbreak.Moreover,all chemicals’non-carcinogenic and carcinogenic risks increased regardless of exposure routes.In the worst scenario(95^(th)percentile),the margin of exposure for citric acid,benzethonium chloride,benzyl-C12-16-alkyldimethyl chlorides,and sodium chlorite of inhalation exposure,and isopropyl alcohol and benzyl-C12-16-alkyldimethyl chlorides of dermal exposure were acceptable(>100)before the COVID-19outbreak but became unacceptable(<100)after the COVID-19 outbreak.Carcinogenic risks of dichlorvos from inhalation and dermal exposure were above acceptable levels(>10^(-6))before and after the COVID-19 outbreak but comparatively high after the COVID-19 outbreak.Additionally,significantly more workers experienced health symptoms after the COVID-19outbreak(p<0.05),with the most common being muscle lethargy(31%),skin/face stinging(28.7%),and breath shortness/neck pain(24.1%).
基金financially supported by the National Natural Science Foundation of China(Nos.21774086 and 21935008)the Natural Science Foundation of Jiangsu Province(No.BK20180093)+1 种基金the Suzhou Municipal Science and Technology Foundation(No.SYS2018026)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Attachment of bacteria and subsequent formation of biofilms on material surfaces lead to serious consequences including infection,contamination and biofouling,posing a prominent threat to human health and causing problems in many industries.Therefore,it is highly desirable to endow the surfaces with antibacterial properties.Traditional antibacterial surfaces are designed via either bacteria-resisting strategy to prevent the initial adhesion of bacteria or bacteria-killing strategy to eradicate any bacteria that attach to the surface.However,these single-function surfaces have their inherent shortcomings and cannot realize long-term efficacy against bacteria.In recent years,various dual-function antibacterial surfaces with both bacteria-resisting and bacteria-killing properties together have been developed,showing better performance for combating surface-attached bacteria and preventing formation of biofilms.In this review,we summarize the recent development of these dual-function antibacterial surfaces.We focus on the design principles and fabrication strategies of such surfaces and highlight the representative examples,which are categorized specifically into two types according to the anti-adhesive and bactericidal properties are simultaneous or switchable.A brief perspective is finally presented on current challenges and future research directions.
基金the funding support from Foshan University,Chinathe Natural Sciences and Engineering Research Council of Canada(NSERC)
文摘Nanoparticles have been used as diagnostic and therapeutic agents in the human medical field for quite some time, though their application in veterinary medicine and animal production is still relatively new. Recently,production demands on the livestock industry have been centered around the use of antibiotics as growth promoters due to growing concern over microbial antibiotic resistance. With many countries reporting increased incidences of antibiotic-resistant bacteria, laws and regulations are being updated to end in-feed antibiotic use in the animal production industry. This sets the need for suitable alternatives to be established for inclusion in feed.Many reports have shown evidence that nanoparticles may be good candidates for animal growth promotion and antimicrobials. The current status and advancements of nanotechnological applications in animal production will be the focus of this review and the emerging roles of nanoparticles for nutrient delivery, biocidal agents, and tools in veterinary medicine and reproduction will be discussed. Additionally, influences on meat, egg, and milk quality will be reviewed.
文摘The use of seawater for industrial cooling is a vital technology that poses some of the most profound environmental impact on the water quality in the Arabian Gulf. Biocide (chlorine) is added to the seawater to control biofouling of the cooling system. This added chlorine reacts with bromide and other chemicals naturally exist in the water to form a wide range of oxidants. Regrettably, reactions between the residual oxidants and natural organic matter in the water lead to formation of toxic halogenated organic compounds that have detrimental effects on the environment when they are discharged into the Gulf. This paper describes the formation of trihalomethanes (THMs) in seawater cooling systems. Results of kinetic experiments have shown that concentrations of THMs increased rapidly with time during the first half hour. Chlorination of seawater has shown significant increase in total THMs (TTHMs) and in bromoform concentrations. Rapid decrease of UV absorbance at 254 nm was also observed during seawater chlorination which is indicative of natural organic matter degradation into small organic molecules including THMs and other by-products. The increase in chlorine dose was accompanied with an increase in TTHMs and bromoform concentrations. Linear relationships between total chlorine concentration and both final TTHMs and bromoform concentrations were established. First order exponential decay and exponential associate functions were developed to correlate chlorine dose with formed THMs.
文摘Background: Annonaceous acetogenins enclose a large number of biological activities, among which the insecticidal stands out. Methods: We report herein the biocide effects of natural acetogenins from Annona squamosa, A.?muricata and A. montana seeds: annonacin, cis-annonacin, cis-annonacin-10- one, asimicin, rolliniastatin-2, cherimolin-1, cherimolin-2, almuñequin, and two β-OH acetogenins: laherradurin and itrabin on Spodoptera frugiperda Smith (Lepidoptera: Noctuidae). Also, some acetylated and methoxy methylated ACG derivatives were synthesized and evaluated: annonacin (3 OAc), annonacin (4 OAc), asimicin (3 OAc), rolliniastatin-2 (3 OAc), rolliniastatin-2 (MOM), laherradurin (3 OAc) and itrabin (3 OAc). Results: The natural acetogenin rolliniastatin-2 (100 μg·g-1 of diet) produced the most important toxic action causing 100% mortality of early instar larvae. Derivatization of ACG yielded compounds that produced nutritional alterations. The incorporation of rolliniastatin-2 (3 OAc) and rolliniastatin-2 (3 MOM) (100 μg·g-1) into the artificial diet of Spodoptera frugiperdadisplayed the strongest antifeedant effects causing marked decreasings in larval growth and adult lethal malformations. Conclusion: Natural acetogenins are promising metabolites for insect control. Derivatization of these compounds reduces their toxicity to early instar larvae.
文摘The science and technology interact with the art in several ways. Biotechnological coupled with analytical approaches can play an important role in protecting and preserving cultural heritage for future generations. Many microorganisms influenced by environmental conditions are the main responsible for biological contamination in built heritage. Biocides based on chemical compounds have been used to mitigate this problem. Thus, it is vitally important to develop proper remediation actions based on environmentally innocuous alternative. Bacillus specie is emerging as an optimistic alternative for built heritage treatment due to their capacity to produce secondary metabolites with antagonistic activities against many fungal pathogens. Therefore, the intent of this work was to access a rapid evaluation of antifungal potential of bioactive metabolites produced by Bacillus strains and simultaneously their characterization using spectroscopic (NMR) and chromatographic techniques (LC-ESI-MS). The high antifungal activity obtained for Bacillus sp. active compounds produced in this study confirms the great potential to suppress biodeteriogenic fungi growth on historical artworks. Additionally, the proposed methodology allowed to access bioactive metabolites produced without need of the laborious total previous isolation and could be used as a viable alternative to be employed for screening and production of new green biocides.
文摘Antimicrobial resistance(AMR)poses a significant threat to public health and is increasingly recognized within the“One Health”framework,which emphasizes the interconnectedness of human,animal,and environmental health.While extensive research has focused on regulating antibiotic use across healthcare and other sectors,the impact of intensive biocide use on AMR development,particularly in seawater-cooled systems,remains underexplored.In this study,we report the isolation and characterization of a multidrug-resistant Klebsiella quasipneumoniae strain from the cooling water system of a coastal power plant,where continuous chlorination at 0.2 ppm is employed for biofouling control.The isolated strain displayed broad-spectrum resistance to multiple biocides and antibiotics.Interestingly,the strain shown enhances biofilm formation in response to biocides and antibiotics,thereby compounding its resistance profile.Efflux assays with ethidium bromide(EtBr)and whole-genome sequencing revealed that efflux pumps are central to the resistance mechanisms.Additionally,the presence ofβ-lactamase(OKP-A)and FosA genes confers resistance to theβ-lactam and epoxide classes of antibiotics.The strain was found to be salt-tolerant and preferred to grow at normal salinity,indicating a non-marine origin of this isolate.These findings highlight the prevalence of biocide and antibiotic-resistant pathogens in marine cooling water systems that primarily rely on biocides for biofouling control.In line with One Health principles,our research advocates for a reassessment of biocide practices in marine cooling water systems and the implementation of proactive measures to mitigate the spread of antimicrobial resistance(AMR).
文摘Seawater desalination is one of the major industrial activities along the coastline of Kuwait that poses profound environmental impact on the quality of seawater.This study focuses on investigating the potential contamination of biocides,volatile organic hydrocarbons(VOCs)and other halogenated hydrocarbons discharged from Az-Zour desalination plant.Chemical contamination by residual chlorine(RC)and some VOCs was detected in effluents from inside and at the vicinity of the plant.RC ranged between 0.15 and 0.49 mg/L while bromoform(CHBr3)was the highest of all the VOCs detected and ranged between 0.22 and 3.30μg/L.Benzinoides(benzene,toluene,xylene and ethylbenzene)were also detected at 0.1μg/L and 0.25μg/L.The levels of RC as measured in the vicinity of the Az-Zour plant are below the limit set up by Kuwait EPA.However,it still poses effects to the nearby aquatic life and therefore,it is important to lower the concentration of RC in the discharge effluent.
文摘Annonaceous acetogenins enclose a large number of biological activities, among which the insecticidal stands out. <em>Spodoptera frugiperda</em> is a pest that affects corn crops among others and has a great capacity to develop resistance to traditional insecticides, which represents sufficient reasons for the search for new alternatives for their control. The objective of this study was to determine the appropriate concentration and screening new natural insecticides against second instar larvae of <em>S. frugiperda</em>, under glasshouse conditions on <em>Zea mays</em> L. Natural products such as annonaceous acetogenins and some acetylated and methoxy methylated ACG derivatives and the commercial product Lambda-cyhalotrin (LC) were evaluated. The percent mortalities of <em>S. frugiperda </em>larvae in glasshouse conditions were recorded after 24, 48 and 72 h of treatment application. The results showed that the acetogenins tested were significantly (P < 0.05) different in relation to pest mortality than untreated check. After 72 h of treatment application the highest percent mortalities were obtained with the mixture of two natural products, rolliniastatin-2 (<strong>5</strong>) (100 μg/mL) + squamocin (<strong>6</strong>) (100 μg/mL) + LC (50 μg/mL) that proved the most effective and gave (100%), while rolliniastatin-2 (<strong>5</strong>) at 100 μg/mL alone, gave lowest percent mortality (65%), followed by squamocin (<strong>6</strong>) at 100 μg/mL (55%) and LC at 50 μg/mL (30%). The acetylated and methoxy methylated ACGs derivatives caused very low mortality (25% - 35%). It is recommended the mixture as a management option of <em>S. frugiperda</em> as a component of integrated pest management. The results allow us to infer that the addition of natural ACGs synergizes the insecticidal activity of the commercial product. Finding a new ecological alternative for insect control.
文摘Emulsive polymerization of mono- and dy(meth)acrylates of butandiol, decid(meth)acrylate, methyl-α-alkilacrylates with industrial acrylic monomers—butylacrylate, methylacrylate, methacrylic acid, methyl(meth)acrylate has been investigated. Structurization of copolymers using dy(meth)acrylates of butandiol, braking of emulsive polymerization using water insoluble biocides, dy(meth)acrylates of butandiol and methyl-α-alkilacrylates have been determined. The mechanism of emulsive polymerization of (meth)acrylic monomers using methyl-α-alkilacrylates has been investigated.
基金financially supported by the National Natural Science Foundation of China(No.51501201)。
文摘The corrosion damage of 20 SiMn steel by sulphate-reducing bacteria(SRB)and the mitigation effect of organic silicon quaternary ammonium salt(OSA)were studied in sterilized mild alkaline simulated concrete pore solution(STR)with different additions of SRB and OSA at pH 9.35 for 28 days.Uniform corrosion occurs in STR medium while slight localized corrosion is observed in STR+OSA medium,and localized pitting corrosion occurs in STR+SRB and STR+SRB+OSA media.The largest pit depth reduces from 36.70μm in STR+SRB medium to 3.31μm in STR+SRB+OSA medium due to the mitigation effect of OSA.The corrosion rate reflected by weight loss and electrochemical impedance spectroscopy(EIS)results presents the order of STR<STR+OSA<STR+SRB+OSA<STR+SRB,which also proves that the presence of SRB can accelerate corrosion in a carbonated medium.However,OSA as an efficient bacteriostatic agent can reduce the excessive growth of SRB and thus reduce corrosion.
基金financial support from Saudi Aramcothe China Scholarship Council for studying in the USA+2 种基金supports by the National Key Research and Development Program of China (No. 2018YFF0215002)Key Laboratory of Materials Chemistry for Energy Conversion and Storage Ministry of Education (2018)The Foundation of Hubei Key Laboratory of Materials Chemistry and Service Failure (2017)。
文摘Tetrakis hydroxymethyl phosphonium sulfate(THPS) was enhanced by a 14-mer Peptide A, with its core12-mer sequence mimicking part of Equinatoxin II protein, in the mitigation of sulfate reducing Desulfovibrio ferrophilus MIC(microbiologically influenced corrosion) of X80 carbon steel. Results proved that50 ppm(w/w) THPS was sufficient to mitigate the D. ferrophilus biofilm, and its very agressive MIC(19.7mg/cm^(2) in 7 days or 1.31 mm/a), but not 20 ppm THPS. To achieve effective mitigation at a low dosage of THPS, biofilm-dispersing Peptide A was added to 20 ppm THPS in the culture medium. Sessile cell counts were reduced by 2-log and 4-log after enhancement by 10 ppb and 100 ppb Peptide A, respectively. Enhancement efficiency(further reduction in corrosion rate) reached 69% for 10 ppb Peptide A and 83% for100 ppb Peptide A compared with 20 ppm THPS alone treatment, indicating that Peptide A was a good biocide enhancer for THPS.
基金financially supported by PTT Exploration and Production, ThailandChinese Society for Corrosion and Protection。
文摘In the oil and gas industry,microbiologically influenced corrosion(MIC) is a major threat to hydrotest,a procedure which is required to certify whether a pipeline can be commissioned.Seawater is frequently used as a hydrotest fluid.In this bio film prevention lab study,an oilfield biofilm consortium was grown in an enriched artificial seawater anaerobically at 37℃ for 60 days.The combination of 100 ppm(w/w) 2,2-dibromo-3-nitrilopropionamide(DBNPA)+100 nM(180 ppb) Peptide A(a biofilm dispersal agent) led to extra SRB(sulfate reducing bacteria),APB(acid producing bacteria) and GHB(general heterotrophic bacteria) sessile cell count reductions of 0.9-log,0.8-log and 0.6-log,respectively,compared with the outcome obtained by using 100 ppm DBNPA only.The Peptide Aenhancement also led to extra reductions of 44 % in weight loss,43 % in maximum pit depth,and 54 % in corrosion current density.
