N-Acyl Homoserine Lactone-Mediated Quorum Sensing System Inhibition of Phenolic Strawberry Extract

Phenolic compounds which have many bioactivities such as antioxidant, antimicrobial and also inhibition of quorum sensing-regulated violacein pigment production properties are one of the plant secondary metabolites. The objective of this study was to determine the antioxidant, antimicrobial activity and the inhibition of quorum sensing (QSI) activity by the phenolic extract obtained from strawberry fruits (Fragaria×ananassa cv. ‘Rubygem’). The phenolic content of extract was determined as 3089 μg GAE g fw-1. The antioxidant activity determined through the ABTS+ and FRAP method was 28.4 and 26.2 mmol TE L-1 respectively. The phenolic extract was able to inhibit all the evaluated bacteria by the disc diffusion assay in the range of 3.12–18.36 mm and could inhibit the quorum sensing phenomena in bacteria. The strawberry phenolic extract exhibited high antioxidant capacity, antimicrobial and anti-quorum sensing properties. To our knowledge, this is the first report on the quorum sensing inhibition activity of strawberry fruit extract. The discovery of non-toxic novel compounds within antibacterial and QSI activity could lead to the development of antimicrobial therapeutic agents that can be alternative and complementary treatments against antibiotic resistant bacterial pathogen

Cellulose-Organic Montmorillonite Nanocomposites as Biomacromolecular Quorum-Sensing Inhibitor

The aim of this study was to develop simple cellulose nanocomposites that can interfere with the quorum-sensing (QS)-regulated physiological process of bacteria, which will provide a sustainable and inexpensive solution to the serious challenges caused by bacterial infections in various products like food packaging or biomedical materials. Three cellulose nanocomposites with 1-5 w% octadecylamine-modified montmorillonite (ODA-MMT) were prepared by regeneration of cellulose from ionic liquid solutions in the presence of ODA-MMT suspension. Structural characterization of the nanocomposites showed that the ODA-MMT can be exfoliated or intercalated, depending on the load level of the nanofiller. Thermal gravimetric analysis showed that the incorporation of ODA-MMT nanofiller can improve the thermal stability of the nanocomposites compared with regenerated cellulose. Evaluation of the anti-QS effect against a pigment-producing bacteria C. violaceum CV026 by disc diffusion assay and flask incubation assay revealed that the QS-regulated violacein pigment production was significantly inhibited by the cellulose nanocomposites without interfering the bacterial vitality. Interestingly, the nanocomposite with the lowest load of ODA-MMT exhibited the most significant anti-QS effect, which may be correlated to the exfoliation of nanofillers. To our knowledge, this is the first report on the anti-QS effect of cellulose nanocomposites without the addition of any small molecular agents. Such inexpensive and nontoxic biomaterials will thus have great potential in the development of new cellulosic materials that can effectively prevent the formation of harmful biofilms

Kaempferol loaded lecithin/chitosan nanoparticles: preparation, characterization, and their potential applications as a sustainable antifungal agent

WOS: 000402039400007PubMed ID: 27265551Flavonoid compounds are strong antioxidant and antifungal agents but their applications are limited due to their poor dissolution and bioavailability. The use of nanotechnology in agriculture has received increasing attention, with the development of new formulations containing active compounds. In this study, kaempferol (KAE) was loaded into lecithin/chitosan nanoparticles (LC NPs) to determine antifungal activity compared to pure KAE against the phytopathogenic fungus Fusarium oxysporium to resolve the bioavailability problem. The influence of formulation parameters on the physicochemical properties of KAE loaded lecithin chitosan nanoparticles (KAE-LC NPs) were studied by using the electrostatic self-assembly technique. KAE-LC NPs were characterized in terms of physicochemical properties. KAE has been successfully encapsulated in LC NPs with an efficiency of 93.8 +/- 4.28% and KAE-LC NPs showed good physicochemical stability. Moreover, in vitro evaluation of the KAE-LC NP system was made by the release kinetics, antioxidant and antifungal activity in a time-dependent manner against free KAE. Encapsulated KAE exhibited a significantly inhibition efficacy (67%) against Fusarium oxysporium at the end of the 60 day storage period. The results indicated that KAE-LC NP formulation could solve the problems related to the solubility and loss of KAE during use and storage. The new nanoparticle system enables the use of smaller quantities of fungicide and therefore, offers a more environmentally friendly method of controlling fungal pathogens in agriculture.Hacettepe University Scientific Research Project [014 D12 101 005-820]; Scientific and Technological Research Council of Turkey (TUBITAK) [2211/C]This work was supported by Hacettepe University Scientific Research Project grant (014 D12 101 005-820) and The Scientific and Technological Research Council of Turkey (TUBITAK) with PhD Scholarship (2211/C)

Electropolymerizations of two novel EDOT-BODIPY zinc oxide nanocomposites and evaluation of their in vitro antibacterial activities

Boron containing materials as novel classes of antibacterial agents have been widely used in coating or medical applications due to their excellent functionality against microorganisms. In this study, two different boron dipyrromethene (BODIPY)/zinc oxide based P(M1-co-Edot)/ZnO and P(M2-co-Edot)/ZnO nanocomposite copolymer materials were prepared. The BODIPY/ZnO nanocomposite films were synthesized using potentiostat. ZnO nanoparticles were used to increase the strength and conductivity of the obtained semiconducting materials. Spectroelectrochemical analysis show that the copolymers, P(M1-co-Edot)/ZnO and P(M2-co-Edot)/ZnO, have electronic band gaps at 1.56 and 2.51 eV and optical band gaps at 2.11 and 2.00 eV, respectively. The synthesized nanocomposite films were characterized by Raman, nuclear magnetic resonance (NMR) and FT-IR spectroscopies. The optical properties of the synthesized monomers and their nanocomposite copolymers were demonstrated using UV-Vis and fluorescence spectroscopy. SEM and AFM images show the surface morphologies of nanocomposite copolymer films and surface roughness of P(M1-co-Edot)/ZnO and P(M2-co-Edot)/ZnO were calculated as Ra = 84.6 nm Rq = 106 nm and 120 nm, respectively. Antibacterial activities of the obtained nanocomposite films prepared in ultrapure water with different concentrations (2.5-0.25 mg/mL) were discovered against Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli) bacteria by using disc diffusion method. The antibacterial activities of obtained films were found to be higher against Gram negative bacteria compared to that of Gram positives. Obtained results show that synthesized nanocomposites with easy production and nontoxic properties can be used as functional bioengineering materials for antibacterial electrochromical materials

Investigation the potential use of silver nanoparticles synthesized by propolis extract as N-acyl-homoserine lactone-mediated quorum sensing systems inhibitor

Tan, Gamze ( Aksaray, Yazar )Background/aim: Quorum sensing (QS) is a chemical communication process that bacteria use to regulate virulence. Inhibition of QS (antiQS) overcomes the pathogenicity of bacteria. Silver nanoparticles (AgNPs) have been used as antimicrobials against pathogens, but have not been used against QS-mediated bacterial infection. Also, studies have been carried out on the inhibitory effects of propolis based structures on pathogen growth, but no studies have been found on their potential use as QS inhibitor. The present study aims to investigate the synthesis and characterization of silver nanoparticles (AgNPs) reduced with propolis extract (P–AgNPs) and evaluation of their antimicrobial and, for the first time, antiQS activity. Materials and methods: P–AgNPs were synthesized using with different volumes (1, 2.5 and 5 mL) of propolis extract (PE) by biological method via reduction of silver nitrate. Synthesized P–AgNPs were characterized in terms of hydrodynamic, chemical, morphological, physical, and antioxidant properties. Disc diffusion and flask incubation assays were used to evaluate the antimicrobial effect against Gram–negative bacteria (Escherichia coli, Proteus mirabilis, Proteus vulgaris, Salmonella typhimurium, Enterobacter aerogenes, Pseudomonas aeruginosa) and Gram–positive bacteria (Staphylococcus aureus, Streptococcus mutans, Bacillus thuringiensis) and QS– regulated biofilm activity against biosensor strain Chromobacterium violaceum CV026. Results: AgNPs were successfully synthesized by biological method via PE. The violacein pigment production based on the QS system was greatly inhibited by the P–AgNPs (inhibition zones: 16.22-21.48 mm and violacein inhibition: 63.16 ± 2.4-75.24 ± 3.5 %) without interfering with the growth of bacteria, which is the first report on the antiQS effect of P–AgNPs. Conclusion: Our results suggest that P–AgNPs may be potentially used to inhibit bacterial physiological processes due to the signal molecules regulates important collective behavior of bacteria. The development of such nontoxic biomaterials may have great potential to evaluate for the new medicinal substance that inhibits the pathogenic biofilms

Antibacterial Activity and Chemical Composition of Essential Oils from Some Galium (Rubiaceae) Species Against Pathogenic Bacteria

In this work, chemical composition and antimicrobial activity of the essential oils of Galium incanum, Galium dieckii ve Galium aladaghense were firstly reported. The essential oils were obtained from the all parts of the plant by hydrodistillation and analyzed by using GC-MS. Antimicrobial activity of synthezied essential oils was carried out against 5 pathogen bacteria Escherichia coli (E. coli) ATCC 25922, Staphylococcus aureus (S. aureus) ATCC 25923, Pseudomonas syringae pv. tomato (P. syringae) DC300, Salmonella enterica serotype Typhmurium (S. typhmurium) SL 1344 and Streptococcus mutans (S. mutans) ATCC 25175. According to the results, it was determined that isolated essential oils comprised of 61 compounds. Compounds of essential oils included that structure monoterpene (8.2%), monoterpenoid (14.75%) and sesquiterpene (14.75%). Unclassified compounds have been identified as other compounds. From the antimicrobial activity was observed that the isolated essential oil from Galium incanum, Galium dieckii ve Galium aladaghense exhibited a potent inhibitory effect against all gram negative and gram positive bacteria with diameter of inhibition zones ranging from 4.3 to 12.3 mm. Essential oil of Galium aladaghense indicated that high antimicrobial activity on all bacteria than Galium incanum and Galium dieckii

Antibacterial Activity and Chemical Composition of Essential Oils from Some Galium (Rubiaceae) Species Against Pathogenic Bacteria

In this work, chemical composition and antimicrobial activity of the essential oils of Galium incanum, Galium dieckii ve Galium aladaghense were firstly reported. The essential oils were obtained from the all parts of the plant by hydrodistillation and analyzed by using GC-MS. Antimicrobial activity of synthezied essential oils was carried out against 5 pathogen bacteria Escherichia coli (E. coli) ATCC 25922, Staphylococcus aureus (S. aureus) ATCC 25923, Pseudomonas syringae pv. tomato (P. syringae) DC300, Salmonella enterica serotype Typhmurium (S. typhmurium) SL 1344 and Streptococcus mutans (S. mutans) ATCC 25175. According to the results, it was determined that isolated essential oils comprised of 61 compounds. Compounds of essential oils included that structure monoterpene (8.2%), monoterpenoid (14.75%) and sesquiterpene (14.75%). Unclassified compounds have been identified as other compounds. From the antimicrobial activity was observed that the isolated essential oil from Galium incanum, Galium dieckii ve Galium aladaghense exhibited a potent inhibitory effect against all gram negative and gram positive bacteria with diameter of inhibition zones ranging from 4.3 to 12.3 mm. Essential oil of Galium aladaghense indicated that high antimicrobial activity on all bacteria than Galium incanum and Galium dieckii.In this work, chemical composition and antimicrobial activity of the essential oils of Galium incanum, Galium dieckii ve Galium aladaghense were firstly reported. The essential oils were obtained from the all parts of the plant by hydrodistillation and analyzed by using GC-MS. Antimicrobial activity of synthezied essential oils was carried out against 5 pathogen bacteria Escherichia coli (E. coli) ATCC 25922, Staphylococcus aureus (S. aureus) ATCC 25923, Pseudomonas syringae pv. tomato (P. syringae) DC300, Salmonella enterica serotype Typhmurium (S. typhmurium) SL 1344 and Streptococcus mutans (S. mutans) ATCC 25175. According to the results, it was determined that isolated essential oils comprised of 61 compounds. Compounds of essential oils included that structure monoterpene (8.2%), monoterpenoid (14.75%) and sesquiterpene (14.75%). Unclassified compounds have been identified as other compounds. From the antimicrobial activity was observed that the isolated essential oil from Galium incanum, Galium dieckii ve Galium aladaghense exhibited a potent inhibitory effect against all gram negative and gram positive bacteria with diameter of inhibition zones ranging from 4.3 to 12.3 mm. Essential oil of Galium aladaghense indicated that high antimicrobial activity on all bacteria than Galium incanum and Galium dieckii

New biobased non-ionic hyperbranched polymers as environmentally friendly antibacterial additives for biopolymers

The aim of this research was to develop new biobased non-ionic polymeric additives with significant bacterial inhibition and low leaching potential, so that they can be used to produce biopolymer materials for various applications such as biomedical devices, surgical textile, or food packaging. Two new non-ionic hyperbranched polymers (HBPs) were prepared by a facile solvent-free polymerization of an AB2-monomer derived from naturally existing molecular building blocks 2-phenylethanol, isatin, and anisole. The molecular structures and thermal properties of the obtained HBPs were characterized by GPC, NMR, FTIR, HRMS, MALDI-TOF, TGA and DSC analyses. Disk diffusion tests revealed that the two obtained HBPs showed more significant antibacterial activity against 9 different food and human pathogenic bacteria, compared with small molecular antibiotics. The maximal antibacterial effect of HBPs was achieved at 2 μg per disk (or 0.1 mg mL−1), which was significantly lower (∼1/15) compared to the linear antibacterial polymer chitosan. Such enhanced antibacterial properties can be attributed to the unique highly branched structures and effectively amplified functionalities of HBPs. Finally, the prepared HBPs were added into natural polymers cellulose and polyhydroxybutyrate (PHB), and the resulting biopolymer films showed no significant leakage after being merged in water for 5 days. This was in sharp contrast to the biopolymer films containing a small model compound, which leaked out significantly under the same conditions. To our knowledge, this is the first report on non-ionic bio-based dendritic macromolecules with significant bacteria inhibition and low leakage

INVESTIGATION OF USE IN WASTEWATER TREATMENT OF NANOFIBERS OBTAINED FROM OSAGE ORANGE FRUIT

16th International Multidisciplinary Scientific Geoconference (SGEM 2016) -- JUN 30-JUL 06, 2016 -- Albena, BULGARIAWOS: 000391648800027The aim of this study was to prepare electrospun chitosan-based nanofiber mats and to incorporate the fruit extracts of Osage Orange (Madura Pomifera) into the mats. Chitosan-ethylenediaminetetraacetic acid/polyvinyl alcohol (CS-EDTA/PVA) was selected as the polymers. The osage orange extracts with 3 wt% were incorporated into the CS-EDTA/PVA solution and electrospun to obtain nanofibers. The morphology and diameters of the mats were analyzed using scanning electron microscopy (SEM). The chemical bonding properties were investigated by fourier transform infrared spectroscopy (FT-IR). Finally, the sorption potential of Osage Orange loaded nanofibers for the removal of common metallic pollutants, cadmium (Cd2+), cobalt (Co2+), copper (Cu2+), nickel (Ni2+) and lead (Pb2+) was also investigated. The results indicated that the diameters of the fibers were on the nanoscale and that no crystals of the extract were observed in the mats. Osage Orange loaded chitosan based nanofiber adsorbent presented good absorption capacity for all tested metals ranged between 29-34%. In conclusion, our experiments demonstrated that biomaterials composed of osage orange loaded CS EDTA nanofibers have a potential adsorbent for heavy metal.Bulgarian Acad Sci, Acad Sci Czech Republ, Latvian Acad Sci, Polish Acad Sci, Russian Acad Sci, Serbian Acad Sci & Arts, Slovak Acad Sci, Natl Acad Sci Ukraine, Inst Water Problem & Hydropower NAS KR, Natl Acad Sci Armenia, Sci Council Japan, World Acad Sci, European Acad Sci Arts & Lett, Acad Sci Moldova, Montenegrin Acad Sci & Arts, Croatian Acad Sci & Arts, Georgian Natl Acad Sci, Acad Fine Arts & Design Bratislava, Turkish Acad Sci, Bulgarian Ind Assoc, Bulgarian Minist Environm & Wate

SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL ACTIVITY OF CHITOSAN/CLAY NANOCOMPOSITES

16th International Multidisciplinary Scientific Geoconference (SGEM 2016) -- JUN 30-JUL 06, 2016 -- Albena, BULGARIAWOS: 000391648800042Clay-based bionanocomposites have gained great attention due to their nanosized functional properties and safe natural structures. Combination at the nanometric scale of the increased surface areas and reactive surfaces of clays with the functional behavior of biopolymers has been pointed out as an attractive way to develop organic-inorganic nanohybrid materials with properties that are inherent to both types of components. In this study a natural-based nanocomposite film consisting of chitosan and organic clay was synthesized. Montmorillonite modified with octadecylamine (ODA-MMT) was used as an organically modified layered silicate. The nanocomposite was prepared by mixing a acetic acid suspension of ODA-MMT with a solution containing chitosan as the macroscopic polymer matrix. The effect of ODA-MMT content (0.5-3%) on the structure and antimicrobial activity of the nanocomposite have been investigated. The interactions between the chitosan matrix and ODA-MMT at different conditions were evaluated using SEM, TEM, XRD and DSC analysis. The results indicated that the formation of exfoliated nanostructure and the thermal stability of nanocomposites was improved within increased loading of nano-dispersed clay in matrix. Antimicrobial activity of chitosan/ODA-MMT nanocomposites was evaluated using disc diffusion method against Gram-positive bacteria Staphylococcus aureus ATCC 25923 and Streptococcus mutans ATCC 25175 and Gram-negative bacteria Escherichia colt ATCC 25922 and Salmonella spp. (Laboratory stock). The antimicrobial activity studies of the nanocomposites showed that the nanocomposites could more strongly inhibit the growth of the tested Gram-positive bacteria than Gram negative bacteria. The inhibitory effect of nanocomposites on microorganisms increased with the increasing content of ODA-MMT. The results showed that the strong antimicrobial activity of the nanocomposites may be related to the interaction and the fine dispersion between chitosan and clay.Bulgarian Acad Sci, Acad Sci Czech Republ, Latvian Acad Sci, Polish Acad Sci, Russian Acad Sci, Serbian Acad Sci & Arts, Slovak Acad Sci, Natl Acad Sci Ukraine, Inst Water Problem & Hydropower NAS KR, Natl Acad Sci Armenia, Sci Council Japan, World Acad Sci, European Acad Sci Arts & Lett, Acad Sci Moldova, Montenegrin Acad Sci & Arts, Croatian Acad Sci & Arts, Georgian Natl Acad Sci, Acad Fine Arts & Design Bratislava, Turkish Acad Sci, Bulgarian Ind Assoc, Bulgarian Minist Environm & Wate