Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2024Scopus SJRQ3Facile biomimetic synthesis of AgNPs using aqueous extract of Helichrysum arenarium: characterization and antimicrobial activity
Yilmaz, Mustafa Tahsin; İspirli, Humeyra; Taylan, Osman; Balubaid, Mohammad; Dertli, Enes
The present study focuses on synthesis of silver nanoparticles (AgNPs) by employment of a green and facile synthesis method. Aqueous extract of Helichrysum arenarium was used as a reducing and capping agent. The bioreduction of silver particles was monitored using UV–Vis spectroscopy based on increase in color intensity led by surface plasmon resonance. SEM, TEM, FTIR, DSC, and XRD analyses were followed for characterization, divulging that the nanoparticles were thermally resistant in the size of approximately 20 nm with a quasi-spherical shape without any agglomeration. AgNPs possessed a nanocrystal form with presence of crystalline Ag. EDAX analysis was used to verify that the nanoparticles were silver as revealed by a typical optical absorption peak of metallic silver nanocrystallites. The AgNPs were shown to have strong antibacterial and antifungal effects on some foodborne pathogens. The method developed in this study could offer a green, facile biomimetic, and cost-effective method.
AtıfScopus3WoS2OpenAlex3
İncele - MakaleAçık Erişim2021Scopus SJRQ1A green nano-biosynthesis of selenium nanoparticles with Tarragon extract: Structural, thermal, and antimicrobial characterization
Yilmaz, Mustafa Tahsin; İspirli, Humeyra; Taylan, Osman; Dertli, Enes
In this study, tarragon extract was used as a reducing agent to perform green nano-biosynthesis of selenium nanoparticles (SeNPs). The synthesized SeNPs were characterized using measurements of UV–Vis spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy disperse analysis of X rays (EDAX), Fourier-transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD) and differential scanning analysis (DSC). Synthesis of nanoparticles was confirmed by observing a peak at 212 nm in UV-VIS, indicating the surface plasmon resonance of SeNPs. Tarragon extract enabled a stable dispersion of SeNPs, giving rise to formation of the nanoparticles in the shape of quasi-spheres without clustering with the sizes between 20 and 50 nm. The SeNPs were shown to be in the form of nanocrystals, having Se embedded in the nanostructure with high thermal stability (a high resistance to thermal process over 200 °C). The SeNPs synthesized with tarragon extract could remarkably increase the inhibition zones from approximately 13 to 18 mm against the pathogenic bacteria and from 10 to 14 mm, 17–36 mm, 8–12 mm, 15–24.5 mm and 9–14 mm, against A. alternata, A. niger, A. parasiticus, B. cinerea, F. oxysporum and P. chrysogenum, respectively.
AtıfScopus86WoS71OpenAlex83İncele - MakaleAçık Erişim2015Scopus SJRQ2Characterization of functional properties of enterococcus faecium strains isolated from human gut
İspirli, Humeyra; Demirbaş, Fatmanur; Dertli, Enes
The aim of this work was to characterize the functional properties of Enterococcus faecium strains identified after isolation from human faeces. Of these isolates, strain R13 showed the best resistance to low pH, bile salts, and survival in the simulated in vitro digestion assay, and demonstrated an important level of adhesion to hexadecane as a potential probiotic candidate. Analysis of the antibiotic resistance of E. faecium strains indicated that in general these isolates were sensitive to the tested antibiotics and no strain appeared to be resistant to vancomycin. Examination of the virulence determinants for E. faecium strains demonstrated that all strains contained the virulence genes common in gut-and food-originated enterococci, and strain R13 harboured the lowest number of virulence genes. Additionally, no strain contained the genes related to cytolysin metabolism and showed hemolytic activity. The antimicrobial role of E. faecium strains was tested against several pathogens, in which different levels of inhibitory effects were observed, and strain R13 was inhibitory to all tested pathogens. PCR screening of genes encoding enterocin A and B indicated the presence of these genes in E. faecium strains. Preliminary characterization of bacteriocins revealed that their activity was lost after proteolytic enzyme treatments, but no alteration in antimicrobial activity was observed at different pHs (3.5 to 9.5) and after heat treatments. In conclusion, this study revealed the functional characteristics of E. faecium R13 as a gut isolate, and this strain could be developed as a new probiotic after further tests.
AtıfScopus41WoS37OpenAlex42
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