scholarly journals The Synergistic Microbiological Effects of Industrial Produced Packaging Polyethylene Films Incorporated with Zinc Nanoparticles

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1198 ◽  
Author(s):  
Szymon Mania ◽  
Mateusz Cieślik ◽  
Marcin Konzorski ◽  
Paweł Święcikowski ◽  
Andrzej Nelson ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Antimicrobial Activity ◽  
Zinc Oxide ◽  
Synergistic Effect ◽  
Antimicrobial Properties ◽  
Zinc Stearate ◽  
Bacterial Strains ◽  
Zinc Compounds ◽  
Global Migration ◽  
Polyethylene Films

Zinc compounds in polyolefin films regulate the transmission of UV-VIS radiation, affect mechanical properties and antimicrobial activity. According to hypothesis, the use of zinc- containing masterbatches in polyethylene films (PE) with different chemical nature—hydrophilic zinc oxide (ZO) and hydrophobic zinc stearate (ZS)—can cause a synergistic effect, especially due to their antimicrobial properties. PE films obtained on an industrial scale containing zinc oxide and zinc stearate masterbatches were evaluated for antimicrobial activity against E. coli and S. aureus strains. The morphology of the samples (SEM), composition (EDX), UV barrier and transparency, mechanical properties and global migration level were also determined. SEM micrographs confirmed the good dispersion of zinc additives in the PE matrix. The use of both masterbatches in one material caused a synergistic effect of antimicrobial activity against both bacterial strains. The ZO masterbatch reduced the transparency of films, increased their UV-barrier ability and improved tensile strength, while the ZS masterbatch did not significantly change the tested parameters. The global migration limit was not exceeded for any of the samples. The use of ZO and ZS masterbatch mixtures enables the design of packaging with high microbiological protection with a controlled transmission for UV and VIS radiation.

Synthesis and antimicrobial properties of new 2-((4-ethylphenoxy)methyl)benzoylthioureas

2011 ◽  
Vol 65 (1) ◽  
Author(s):  
Carmen Limban ◽  
Alexandru Missir ◽  
Ileana Chirita ◽  
George Nitulescu ◽  
Miron Caproiu ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Quantitative Methods ◽  
Antimicrobial Properties ◽  
Phenyl Group ◽  
Inhibitory Effect ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Fungal Strains ◽  
Qualitative And Quantitative Methods

AbstractNew acylthiourea derivatives, 2-((4-ethylphenoxy)methyl)-N-(phenylcarbamothioyl)benzamides, were tested by qualitative and quantitative methods on various bacterial and fungal strains and proved to be active at low concentrations against Gram-positive and Gram-negative bacteria as well as fungi. These compounds were prepared by the reaction of 2-((4-ethylphenoxy)methyl)benzoyl isothiocyanate with various primary aromatic amines, and were characterised by melting point and solubility. The structures were identified by elemental analysis, 1H and 13C NMR, and IR spectral data. The level of antimicrobial activity of the new 2-((4-ethylphenoxy)methyl)benzoylthiourea derivatives was dependent on the type, number and position of the substituent on the phenyl group attached to thiourea nitrogen. The iodine and nitro substituents favoured the antimicrobial activity against the Gram-negative bacterial strains, while the highest inhibitory effect against Gram-positive and fungal strains was exhibited by compounds with electron-donating substituents such as the methyl and ethyl groups.

Experiments on the Preparation of Transparent Vulcanized Rubbers

1943 ◽  
Vol 16 (2) ◽  
pp. 445-452
Author(s):  
E. B. Johnson ◽  
J. R. Scott
Keyword(s):  
Mechanical Properties ◽  
Zinc Oxide ◽  
Tensile Properties ◽  
Organic Dyes ◽  
Magnesium Carbonate ◽  
Zinc Stearate ◽  
Permanent Set ◽  
Zinc Carbonate ◽  
Aging Properties ◽  
Made In

Abstract 1. It has been found possible, by the use of combinations of organic accelerators, to prepare accelerated rubbers which contain sufficient zinc oxide for activation but show no trace of pigmentation by the oxide, and are quite as transparent as a mixture containing only rubber and sulfur, and often lighter in color than the latter mixture. These accelerated rubbers have excellent tensile properties. The aging properties vary considerably according to the accelerators used, but in most cases are very good, even if the rubber is over-cured. It is, therefore, possible to make nonblooming rubbers without danger of bad aging. 2. Tests with other activators (zinc carbonate, zinc oleate, and zinc stearate plus magnesium carbonate) showed that these are less effective than zinc oxide, for the vulcanizates obtained had inferior mechanical properties and, in the case of zinc carbonate and oleate, showed a strong tendency to bloom. 3. A combination of accelerators which has been stated to work well without activator was shown to vulcanize very quickly, but to give poor mechanical properties, 4. The tendency of various accelerators to give rubbers, the surfaces of which are easily marked by scratching, presumably owing to efflorescence of accelerator, was noted. 5. The most promising of the mixtures tested for making transparent vulcanized rubbers was one accelerated with diphenylguanidine plus mercapto- benzothiazole, with zinc oxide as activator (mixture F). 6. A mixture is described (mixture K) which gives better aging when vulcanized beyond the optimum tensile properties than when vulcanized short of the optimum cure. 7. Rubbers can be toughened by the use of organic accelerators so as to possess greater resilience and lower permanent set than if toughened by the usual inorganic reinforcing agents. The aging tests described above were all made in the absence of light. For transparent rubber goods which are exposed to light during use, the addition of antioxidants and (or) softeners might be found necessary to give resistance to deterioration by light. In connection with fancy goods, the staining of paper in contact with the rubber may be of importance, and in such cases the choice of accelerators and antioxidants must be made with this in mind. The staining effects of numerous accelerators and antioxidants have already been described. In conclusion, it should be added that the experiments were directed in the first instance towards the production of brown transparent rubbers, for which reason smoked sheet was used. Where a light-colored vulcanizate is required, and especially when it is desired to obtain colored rubbers by adding organic dyes, the use of pale crepe is essential.

scholarly journals Antimicrobial activity of root canal filling materials

2021 ◽  
Vol 7 (1) ◽  
pp. 01-05
Author(s):  
Jikia Maia
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Zinc Oxide ◽  
Antimicrobial Properties ◽  
Root Canal Filling ◽  
Root Canals ◽  
Filling Materials ◽  
Zinc Oxide Eugenol ◽  
Test Culture

The antimicrobial activity of filling materials was studied to improve the quality of treatment of complicated caries in vitro. Resorcin-formalin cement Resodont (“Latus”, Ukraine) - № 1; Endocort zinc oxide-eugenol cement (“Latus”, Ukraine) - No. 2; materials based on zinc oxide eugenol cement with dexamethasone: Endomethasone ivory (Septodont, France) - No. 3 and Endofil ("Produit Dentaires SA", Switzerland) - No. 4. To assess the antimicrobial activity of the studied materials, test microorganism strains were used: Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 6783, Candida albicans ATCC 885-653. As a result of the study, it was established that filling materials have different antimicrobial activity. Resodont has the greatest antimicrobial activity on the test culture. Endomethason is active in relation to the test cultures studied, inferior to Resodont in its antimicrobial properties. Endocort and Endofil have less antimicrobial activity than Resodont and Endomethason, but have approximately equal growth retardation rates. It should be noted that with respect to Staphylococcus aureus, Endocort was found to be almost 1.5 times more active than Endofil. The conducted studies confirm that the materials for filling of root canals by Resodont and Endocort (Latus, Ukraine) have a pronounced antibacterial effect. They are competitive with foreign sealers and are the materials of choice, having a significantly lower cost.

Chemical Composition and Antimicrobial Activity of Teucrium Capitatum L. Subsp. Lusitanicum (Schreb.) T. Navarro & Rosua Essential Oil

2020 ◽  
Author(s):  
Haïfa Debbabi ◽  
Ridha El Mokni ◽  
Ibrahim Jlassi ◽  
Rajesh K Joshi ◽  
Saoussen Hammami
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Essential Oil ◽  
Antimicrobial Properties ◽  
Significant Activity ◽  
Bacterial Strains ◽  
Gram Positive Bacteria ◽  
Sesquiterpene Hydrocarbons ◽  
Germacrene D

Abstract Chemical composition and antimicrobial activity of Teucrium capitatum L. subsp. lusitanicum essential oil was investigated for the first time in the present study. Qualitative and quantitative analyses of the chemical composition by gas chromatography and mass spectrometry (GC–FID and GC–MS) revealed the presence of 60 compounds representing 97.6% of the whole constituents. The main compounds were germacrene D (47.1%), spathulenol (5.8%), α-selinene (5.3%), germacrene A (2.9%), δ-cadinene (2.8%) and cubenol (2.7%). In vitro, the antimicrobial activity was investigated against five bacterial strains along with the yeast Candida albicans using broth microdilution assay. T. capitatum subsp. lusitanicum essential oil showed significant activity against the gram-positive bacteria Staphylococcus aureus (MIC = MBC = 78 μg mL−1), Bacillus subtilis (MIC = MBC = 156 μg mL−1) and the yeast C. albicans (MIC = MFC = 156 μg mL−1). The great potential of antimicrobial effects is most likely due to the very high percentage of sesquiterpene hydrocarbons particularly to germacrene D, for which the antimicrobial properties have been previously reported.

scholarly journals Antimicrobial Activity and Prevention of Bacterial Biofilm Formation of Silver and Zinc Oxide Nanoparticle-Containing Polyester Surfaces at Various Concentrations for Use

Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 442 ◽  
Author(s):  
Fabio Fontecha-Umaña ◽  
Abel Guillermo Ríos-Castillo ◽  
Carolina Ripolles-Avila ◽  
José Juan Rodríguez-Jerez
Keyword(s):  
Antimicrobial Activity ◽  
Zinc Oxide ◽  
Biofilm Formation ◽  
Antimicrobial Properties ◽  
Bacterial Biofilm ◽  
Antimicrobial Efficacy ◽  
Ag Nps ◽  
Zno Nps ◽  
E Coli ◽  
Food Contact Surfaces

Food contact surfaces are primary sources of bacterial contamination in food industry processes. With the objective of preventing bacterial adhesion and biofilm formation on surfaces, this study evaluated the antimicrobial activity of silver (Ag-NPs) and zinc oxide (ZnO-NPs) nanoparticle-containing polyester surfaces (concentration range from 400 ppm to 850 ppm) using two kinds of bacteria, Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli), and the prevention of bacterial biofilm formation using the pathogen Listeria monocytogenes. The results of antimicrobial efficacy (reductions ≥ 2 log CFU/cm2) showed that at a concentration of 850 ppm, ZnO-NPs were effective against only E. coli (2.07 log CFU/cm2). However, a concentration of 400 ppm of Ag-NPs was effective against E. coli (4.90 log CFU/cm2) and S. aureus (3.84 log CFU/cm2). Furthermore, a combined concentration of 850 ppm Ag-NPs and 400 ppm ZnO-NPs showed high antimicrobial efficacy against E. coli (5.80 log CFU/cm2) and S. aureus (4.11 log CFU/cm2). The results also showed a high correlation between concentration levels and the bacterial activity of Ag–ZnO-NPs (R2 = 0.97 for S. aureus, and R2 = 0.99 for E. coli). They also showed that unlike individual action, the joint action of Ag-NPs and ZnO-NPs has high antimicrobial efficacy for both types of microorganisms. Moreover, Ag-NPs prevent the biofilm formation of L. monocytogenes in humid conditions of growth at concentrations of 500 ppm. Additional studies under different conditions are needed to test the durability of nanoparticle containing polyester surfaces with antimicrobial properties to optimize their use.

Organic additives as antimicrobial agents in thermoplastics compounds

2016 ◽  
Vol 1817 ◽  
Author(s):  
Daiane Tomacheski ◽  
Michele Pittol ◽  
Vanda F. Ribeiro ◽  
Ruth M. C. Santana
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Antimicrobial Agents ◽  
Antimicrobial Properties ◽  
Organic Additives ◽  
Bacterial Strains ◽  
Melt Mixing ◽  
Polymeric Matrices ◽  
E Coli ◽  
Scanning Electron

ABSTRACTDevelopment of polymers with antimicrobial characteristics can avoid deterioration and assist in containing spread of pathogens harmful to human health. This study aimed to compare the antimicrobial and mechanical properties of polymeric matrices containing organic antimicrobial additives. Silver organomodified bentonite (Ag_bentonite) and organochlorine molecule in a masterbatch based polyethylene (Cl_PE) were tested in proportion of 2% in a thermoplastic elastomeric formulation. The polymeric matrices were prepared by melt mixing and evaluated in tensile and antimicrobial properties against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) strains. The additives were characterized by thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The nanoscale of Ag_bentonite was verified by SEM. TGA assay showed that Cl_PE is more sensitive to heat than Ag_bentonite. As a result of this lower thermal stability, the addition of Cl_PE reduced the tensile properties of the compound. The sample with Cl_PE was effective against both bacterial strains, reducing the populations of S. aureus and E. coli in 99 and 96%, respectively. The addition of Ag_bentonite did not affect the tensile strength and decreased in 97 and 40% S. aureus and E. coli populations, respectively. The results indicate that the use of organic additives is promissory, but further modifications in processing must be necessary.

scholarly journals Combining Essential Oils of Piper betle and Myristica fragrans for Enhanced Antimicrobial Properties

1970 ◽  
Vol 3 (1) ◽  
pp. 35-42
Author(s):  
Siong Fong Sim ◽  
Fazia Mohd Sinang ◽  
Diana Kertini ◽  
Felecia Collick ◽  
Mellisa Edwand Dankan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Synergistic Effect ◽  
Essential Oils ◽  
Aspergillus Flavus ◽  
Antimicrobial Properties ◽  
Piper Betle ◽  
Chemical Compositions ◽  
Volatile Oils ◽  
Improved Performance

This paper reports the chemical compositions and antimicrobial activity of essential oils extracted fromMyristica fragrans and Piper betle in individual and combined fractions. Enhanced antimicrobial activity isanticipated when the volatile oils are combined as compounds present in different extracts could complementeach other resulting in synergistic effect offering a broader spectrum of microbial resistance. The GC-MSanalysis indicates that chemical compositions of M. fragrans and P. betle vary with M. fragrans containingmore early-eluting compounds. The combined extract is characterised by compounds present in both extracts,some appear to co-elute in the mixture. The antimicrobial activity of the single and combined extracts againstStaphylococcus aureus, Escherichia coli and Aspergillus flavus were evaluated. P. betle demonstrates strongerantimicrobial activity than M. fragrans; the combined extract exhibit improved performance especially on A.flavus.

scholarly journals Antimicrobial Properties of 6-Bromoeugenol and Eugenol

2016 ◽  
Vol 53 ◽  
pp. 57-64
Author(s):  
Radia Mahboub ◽  
Faiza Memmou
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Inhibitory Concentration ◽  
Antimicrobial Properties ◽  
Diffusion Method ◽  
Disc Diffusion ◽  
Bacterial Strains ◽  
Disc Diffusion Method ◽  
Modest Activity

We have studied the antimicrobial properties of 6-bromoeugenol and eugenol by three strains:Pseudomonas aeruginosa(S1),Escherichia coli(S2) andStaphylococcus aureus(S3). We have determined the minimum inhibitory concentration (MIC) for a range of concentrations using the disc diffusion method. We note that all samples present an antimicrobial activity toward the tested bacterial strains at different concentrations (1, 0.5 and 0.25 mg/ml). The 6-bromoeugenol gives modest activity with (S1) and (S3). Eugenol reacts positively with thePseudomonas aeruginosa(S1) at all concentrations and with theEscherichiacoli(S2) at 0.5 mg/ml. We remark that thePseudomonas aeruginosa(S1) is the more sensitive strain thanEscherichiacoli(S2) andStaphylococcus aureus(S3). We have estimated the activity coefficient which has confirmed the antimicrobial activity of the different samples. So, 6-bromoeugenol has shown his efficiency as antimicrobial agent.

scholarly journals Evaluation of Antimicrobial Activity of Buforin I and Nisin and the Synergistic Effect of Their Combination as a Novel Antimicrobial Preservative

2020 ◽  
Vol 83 (11) ◽  
pp. 2018-2025 ◽  
Author(s):  
SAHAR ROSHANAK ◽  
FAKHRI SHAHIDI ◽  
FARIDEH TABATABAEI YAZDI ◽  
ALI JAVADMANESH ◽  
JEBRAEIL MOVAFFAGH
Keyword(s):  
Antimicrobial Activity ◽  
Synergistic Effect ◽  
Antimicrobial Peptides ◽  
Antimicrobial Agents ◽  
Antimicrobial Properties ◽  
Food Spoilage ◽  
Food Preservatives ◽  
Minimum Fungicidal Concentration ◽  
E Coli ◽  
Spoilage Microorganisms

ABSTRACT One of the most effective methods for increasing the antimicrobial activity of a substance is to combine it with one or more other antimicrobial agents. The aim of the present study was to evaluate the antimicrobial effect of buforin I and nisin alone and investigate the synergistic action of these compounds against the most important food spoilage microorganisms, including Bacillus subtilis, Staphylococcus epidermidis, Listeria innocua, Escherichia coli, Salmonella serovar Enteritidis, Aspergillus oryzae, Rhodotorula glutinis, and Geotrichum candidum. The results of MIC and MBC or minimum fungicidal concentration examinations showed that buforin I had higher antimicrobial activity than nisin on all microbial strains used in this study (P ≤ 0.5). E. coli was the most resistant to both antimicrobial agents, whereas L. innocua and S. epidermidis were the most sensitive to nisin and buforin I, respectively. The results of synergistic interaction between buforin I and nisin indicated that the combination of buforin I and nisin on B. subtilis, S. epidermidis, and A. oryzae showed a synergistic effect, whereas it had no effect on Salmonella serovar Enteritidis and G. candidum. The combination of buforin I and nisin showed a partial synergistic effect on L. innocua, E. coli, and R. glutinis. Assessment of viability of the microorganisms under the antimicrobial agents alone and in combination with each other at MICs and fraction inhibitory concentrations indicated that use of these antimicrobial agents in combination enhances antimicrobial activity at lower concentrations of both agents. The present study investigated the antimicrobial properties of buforin I against food spoilage microorganisms for the first time and suggests that its use alone or with nisin may provide a clear horizon for the application of antimicrobial peptides as natural preservatives. Thus, the combination of antimicrobial peptides and traditional antimicrobial food preservatives could be a promising option for the prevention of contamination, spoilage, and infestation of food and beverage products. HIGHLIGHTS

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