scholarly journals Transparent Nanocrystallite Silver for Antibacterial Coating

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
W. Ahliah Ismail ◽  
Zainal Abidin Ali ◽  
R. Puteh

Transparent sol-gel film with antibacterial coating property incorporating silver nanoparticles has been successfully developed. Silver nanoparticles were synthesized by precipitation method at room temperature. XRD structural studies show that crystallite sizes in the range of 18 nm to 40 nm were produced. The coating system used methyltrimethoxy silane as binder and N-propanol as diluent to obtain the highest transperancy. 2.5% wt of nanosilver crystallites was added as antibacterial agent. The coating mixture was applied onto glass plates using sponges and tested againstStaphylococcus aureus,Escherichia coli, andPseudomonas aeruginosa. Values of antimicrobial activity of 4.6, 7.2, and 4.2 were, respectively, obtained forStaphylococcus aureus,Escherichia coliandPseudomonas Aeruginosa. Coating with antimicrobial activity greater than 2 classified as antibacterial.

2011 ◽  
Vol 63 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Gordana Zavisic ◽  
Zeljka Radulovic ◽  
Valentina Vranic ◽  
Jelena Begovic ◽  
L. Topisirovic ◽  
...  

The aim of this study was to investigate the probiotic potential of bacteriocin-producing lactobacilli strain Lactobacillus plantarum G2 isolated from the vaginal mucus of healthy women. The antimicrobial effect of G2 was confirmed in the mixed culture with pathogenic Escherichia coli, Staphylococcus aureus, Salmonella abony and Pseudomonas aeruginosa, while bacteriocine activity was detected against S. aureus and S. abony only. The strain showed an excellent survival rate in low pH and in the presence of bile salts. The percentage of adhered cells of L. plantarum G2 to hexadecane was 63.85?2.0 indicating the intermediate hydrophobicity.


2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Pavithra L. Jayatilake ◽  
Helani Munasinghe

Endophytic and rhizosphere fungi are understood to be aiding the host plant to overcome a range of biotic and abiotic stresses (nutrition depletion, droughts, etc.) hence, they remain to be reservoirs of plethora of natural products with immense use. Consequently, this investigation of endophytic and rhizosphere fungi isolated from Mikania cordata (a perennial vine that is well established in Sri Lanka) for their antimicrobial properties was performed with the aim of future derivation of potential beneficial pharmaceutical products. Leaves, twigs, and roots of M. cordata were utilized to isolate a total of 9 endophytic fungi out of which the highest amount (44%) accounted was from the twigs. A sample of the immediate layer of soil adhering to the root of M. cordata was utilized to isolate 15 rhizosphere fungi. Fusarium equiseti and Phoma medicaginis were endophytes that were identified based on colony and molecular characteristics. The broad spectrum of antimicrobial activity depicted by F. equiseti (MK517551) was found to be significantly greater (p≤0.05, inhibitory against Bacillus cereus ATCC 11778, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 25853) than P. medicaginis (MK517550) (inhibitory against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 25853) as assessed using the Kirby-Bauer disk diffusion method. Trichoderma virens and Trichoderma asperellum were rhizospere fungi that exhibited remarkable antimicrobial properties against the test pathogens chosen for the study. T. asperellum indicated significantly greater bioactivity against all four bacterial pathogens and Candida albicans ATCC 10231 under study. The ranges of minimum inhibitory concentrations (MICs) of the fungi depicting antimicrobial properties were determined. The results obtained suggest that F. equiseti, P. medicaginis, T. asperellum, and T. virens of M. cordata harness bioprospective values as natural drug candidates. This is the first report on isolation and evaluation of the antimicrobial properties of endophytic and rhizosphere fungi of Mikania cordata.


2018 ◽  
Vol 13 (4) ◽  
pp. 1934578X1801300
Author(s):  
Daniyar Sadyrbekov ◽  
Timur Saliev ◽  
Yuri Gatilov ◽  
Ivan Kulakov ◽  
Roza Seidakhmetova ◽  
...  

A cyclopropane derivative of limonene, (1 S, 4 S, 6 R)-7,7-dichloro-4-[(1 S)-2,2-dichloro-1-methylcyclopropyl]-1-methylbicyclo [4.1.0] heptane (compound 2), was synthesized and its structure was determined by NMR and X-ray crystallographic methods. In addition, an antimicrobial activity of the compound against Gram-positive ( Staphylococcus aureus, Bacillus subtilis) and Gram-negative ( Escherichia coli, Pseudomonas aeruginosa) bacterial strains was also scrutinized.


Medicina ◽  
2008 ◽  
Vol 44 (12) ◽  
pp. 977 ◽  
Author(s):  
Alvydas Pavilonis ◽  
Algirdas Baranauskas ◽  
Ligita Puidokaitė ◽  
Žaneta Maželienė ◽  
Arūnas Savickas ◽  
...  

Objective. To evaluate the antimicrobial activity of soft and purified propolis extracts. Study object and methods. Antimicrobial activity of soft and purified propolis extracts was determined with reference cultures of Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 33499, Pseudomonas aeruginosa ATCC 27853, Proteus mirabilis ATCC 12459, Bacillus subtilis ATCC 6633, Bacillus cereus ATCC 8035, and fungus Candida albicans ATCC 60193. Microbiological tests were performed under aseptic conditions. Minimum inhibitory concentration (MIC) – the highest dilution of preparation (the lowest concentration of preparation) that suppresses growth of reference microorganisms – was determined. Results. Concentration of phenolic compounds in soft propolis extract that possesses antimicrobial activity against gram-positive (Staphylococcus aureus, Enterococcus faecalis) and gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis) is 0.587±0.054 mg and 0.587±0.054–0.394±0.022 mg (P>0.05) and in purified propolis extract – 0.427±0.044 mg and 0.256±0.02 mg (P>0.05). Klebsiella pneumoniae is most resistant to soft propolis extract when the concentration of phenolic compounds is 1.119± 0.152 mg and to purified propolis extract when the concentration of phenolic compounds is 1.013±0.189 mg (P>0.05). Spore-forming Bacillus subtilis bacteria are more sensitive to soft and purified propolis extracts when the concentration of phenolic compounds is 0.134±0.002 mg and 0.075±0.025 mg, respectively, and Bacillus cereus – when the concentration is 0.394±0.022 mg and 0.256±0.02 mg (P>0.05). Sensitivity of fungus Candida albicans to soft and purified propolis extracts is the same as Bacillus subtilis. Encapsulated bacterium Klebsiella pneumoniae is most resistant to antimicrobial action of soft and purified propolis extracts as compared with gram-positive Staphylococcus aureus and Enterococcus faecalis bacteria (P<0.05), gram-negative Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis (P<0.05), sporeforming Bacillus subtilis and Bacillus cereus bacteria (P<0.05), and fungus Candida albicans (P<0.05). There is no statistically significant difference between antimicrobial effect of soft propolis extract and purified propolis extract on gram-positive bacteria, gram-negative bacteria, spore-forming bacteria, encapsulated bacteria, and Candida fungus. Conclusions. Soft and purified propolis extracts possess antimicrobial activity. They could be recommended as natural preservatives in the manufacture of pharmaceutical products.


2020 ◽  
Vol 4 (1) ◽  
pp. 49
Author(s):  
Gracielle Oliveira Sabbag Cunha ◽  
Ana Paula Terezan ◽  
Andreia Pereira Matos ◽  
Marcela Carmen De Melo Burger ◽  
Paulo Cezar Vieira ◽  
...  

This study evaluated the antimicrobial activity of isolated compounds and semisynthetic derivatives from Miconia ferruginata (Melastomataceae) against five microorganisms: Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Bacillus subtilis (ATCC 6623), Pseudomonas aeruginosa (ATCC 15442), and Candida albicans (ATCC 10231). The isomeric mixture of ursolic and oleanolic acids was active against S. aureus (MIC = 250 μg mL-1) and against E. coli, B. subtilis, and P. aeruginosa (MIC = 500 μg mL-1). The flavone 5,6,7-trihydroxy-4’-methoxyflavone and the methyl esters, semisynthetic derivatives of a mixture of ursolic and oleanolic acids, showed no activity against the tested microorganisms. These results suggest that the carboxyl group present in the triterpenes may contribute to antimicrobial activity.


2004 ◽  
Vol 3 (1) ◽  
pp. 73-77 ◽  
Author(s):  
Slavica Ilic ◽  
Sandra Konstantinovic ◽  
Zoran Todorovic

Different extracts containing bioactive components and etheric oil of the flowers of Linum capitation kit. (Linacea) of Serbian origin were tested for an Antimicrobial activity against four bacteria (Staphylococcus aureus Escherichia coli, Bacillus subtilus, Pseudomonas aeruginosa), one mold (Aspergillus niger) and one yeast (Candida albicans). The isolated Flavonoids were also tested against Staphylococcus aureus, Escherichia coli Bacillus anhtracis, Pseudomonas aeruginosa, Aspergillus niger, Candida albicans and Herpes simplex virus type.


2019 ◽  
Vol 9 (04) ◽  
pp. 678-681
Author(s):  
Ashraf S Hassan ◽  
Khawlah J Khalaf ◽  
Hamzia A Ajah

The present study demonstrates the effect of storage period on silver nanoparticles (AgNPs), which synthesized by Pseudomonas aeruginosa and their antibacterial activity. The result shows that the size of (AgNPs) which synthesis by Pseudomonas aeruginosa was 93.55nm after 4-72hour, and when storage about 2 years, we found that the size of AgNPs was stable and reduced to 69.0nm. Antibacterial activity against pathogenic microbes: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Serratia sp,Streptococcus sp , Klebsiella sp, Candida albicans was performed before and after storage and found that AgNPs have activity against this microbes.


Author(s):  
GANDONOU Dossa Clément ◽  
BAMBOLA Bouraïma ◽  
TOUKOUROU Habib ◽  
GBAGUIDI Ahokannou Fernand ◽  
DANSOU Christian ◽  
...  

Present study involves the study of the chemical composition of the essential oils extracted from the leaves by gas chromatography and gas chromatography coupled with mass spectrometry of Lippia multiflora harvested in the regions of Kétou, Savalou, Bohicon and Mono and tested by the well diffusion method against pathogenic microorganisms. The essential oils studied are terpene compounds, aromatic compounds, aliphatic compounds and other natural substances. The inhibition zone diameters determined allowed us to evaluate their degree of germ sensitivity of the strains tested. Essential oils extracted from Lippia multiflora harvested in these areas have the most pronounced antimicrobial activity. In total, the essential oils tested have different and specifically a degree of sensitivity against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Proteus mirabilis A24974, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa except that harvested in the Savalou who does not have no degree of sensitivity on Pseudomonas aeruginosa. This work paves the way for food preservation with extracted natural substances and also the formulation of natural antimicrobials for this fact.


2021 ◽  
Author(s):  
Sanjay Ratan Kumavat ◽  
SATYENDRA MISHRA

Abstract Plants are emerging as a cost-effective and ecofriendly method for green synthesis of nanoparticles. The plant extract Launaea procumbens was used as a reduction agent in the green synthesis of silver nanoparticles. UV-Visible spectroscopy, HR-TEM, SAED, FE-SEM, EDAX, DLS, and FT-IR were used to study the green synthesized silver nanoparticles. UV-Vis spectroscopy of a prepared silver solution revealed maximum absorption at 435 nm. The synthesized silver nanoparticles were found to be spherical in shape with a size in the range of 24.28 to 31.54 nm. DLS analysis was used to determine the size of the green synthesized silver nanoparticles, which showed outstanding antibacterial action against Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus, as well as Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. Gram-positive Bacillus subtilis had a maximum zone of inhibition of 20 mm, Staphylococcus aureus had a zone of inhibition of 19 mm, and Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa had zones of inhibition of 13 mm.


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