WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 13Citation - Scopus: 17Characterization of Antimicrobial Activities of Olive Phenolics on Yeasts Using Conventional Methods and Mid-Infrared Spectroscopy(Springer, 2019) Canal, Canan; Özen, Banu; Baysal, Ayşe HandanOlive fruit is very rich in terms of phenolic compounds. Antimicrobial activities of various phenolic compounds against bacteria and fungi are well established; however, their effects on yeasts have not been examined. Aim of this study was to investigate the antimicrobial effects induced by olive phenolic compounds, including tyrosol, hydroxytyrosol, oleuropein, luteolin and apigenin against two yeast species, Aureobasidium pullulans and Saccharomyces cerevisiae. For this purpose, yeasts were treated with various concentrations (12.5-1000ppm) of phenolic compounds and reduction in yeast population was followed with optical density measurements with microplate reader, yeast colony forming units and mid-infrared spectroscopy. All phenolic compounds were effective on both yeasts, especially 200ppm and higher concentrations have significant antimicrobial activity; however, effects of lower levels depend on the type of phenolic compound. According to mid-infrared spectral data, significant changes were observed in 1200-900cm(-1) range corresponding to carbohydrates of yeast structure as a result of exposure to all phenolic compounds except tyrosol. Spectra of tyrosol and luteolin treated yeasts also showed changes in 1750-1500cm(-1) related to amide section and 3600-3000cm(-1) fatty acid region. Since phenolic compounds from olives were effective against yeasts, they could be used in food applications where yeast growth showed problem. In addition, FTIR spectroscopy could be successfully used to monitor and characterize antimicrobial activity of phenolic compounds on yeasts as complementary to conventional microbiological methods.Article Citation - WoS: 96Citation - Scopus: 113Hypericum Perforatum Incorporated Chitosan Films as Potential Bioactive Wound Dressing Material(Elsevier Ltd., 2017) Güneş, Seda; Tıhmınlıoğlu, FundaRecent studies in wound dressing applications offer new therapies and promote wound healing process. The aim of this study was to develop Hypericum perforatum (St John's Wort) oil incorporated chitosan films for wound dressing applications. H. perforatum oil as a potential therapeutic agent was encapsulated in chitosan film to achieve a better wound dressing material. Oil incorporated chitosan films were successfully prepared by solvent casting method in different oil concentrations (0.25–1.5%v/v). Water vapor permeability (WVP), mechanical test, swelling behavior and surface hydrophobicity were performed in order to characterize the prepared films. Antimicrobial test was performed by disc diffusion method and the growth inhibition effects of the films including different amount of H. perforatum oil were investigated on Escherichia coli and Staphylococcus aureus. WVP increased with oil incorporation and the highest value was obtained for 0.25% oil concentration.The highest strain value was obtained in 0.25% oil content films although tensile stress decreased with increasing oil content. H. perforatum oil incorporated films had antimicrobial effect on both microorganisms. Chitosan based films had no cytotoxic effects on NIH3T3fibroblast cells and provided a good surface for cell attachment and proliferation. The results showed that the H. perforatum incorporated chitosan films seems to be a potential and novel biomaterial for wound healing applications.Article Citation - WoS: 21Citation - Scopus: 19In vitro antimicrobial screening of Aquilaria agallocha roots(African Ethnomedicines Network, 2016) Canlı, Kerem; Yetgin, Ali; Akata, Ilgaz; Altuner, Ergin Muratackground: It was previously shown that some parts of Aquilaria agallocha, which is commonly known as oud or oodh, such as roots have been used as a traditional medical herbal in different countries. In Turkey A. agallocha is one of the ingredients while preparing famous Mesir paste, which was invented as a medicinal paste and used from the Ottoman period to now at least for 500 years. The identification the in vitro antimicrobial activity of ethanol extract of A. agallocha roots is main purpose of this analysis. Materials and Methods: By using 17 bacteria and 1 fungi, which include Bacillus, Candida, Enterobacter, Enterococcus, Escherichia, Klebsiella, Listeria, Pseudomonas, Salmonella and Staphylococcus genera, the activity of A. agallocha root extracts were analysed by the help of the disk diffusion method, that is one of the methods commonly used to determine antimicrobial activities. Results: As a result of the study it was observed that ethanol extracts of A. agallocha roots have a clear antimicrobial activity against nearly all microorganism used in the study, but only two bacteria namely E. coli ATCC 25922 and S. typhimurium SL 1344. Conclusion: According to the disk diffusion test results it may be possible to propose that A. agallocha roots should have a medicinal uses especially against E. faecium, L. monocytogenes ATCC 7644, B. subtilis DSMZ 1971, C. albicans DSMZ 1386, S. epidermidis DSMZ 20044 and S. aureus ATCC 25923.Article Citation - WoS: 30Citation - Scopus: 35Bioactive Sheath/Core Nanofibers Containing Olive Leaf Extract(John Wiley and Sons Inc., 2016) Doğan, Gamze; Başal, Güldemet; Bayraktar, Oğuz; Özyıldız, Figen; Uzel, Ataç; Erdoğan, İpekThis study aimed at producing silk fibroin (SF)/hyaluronic acid (HA) and olive leaf extract (OLE) nanofibers with sheath/core morphology by coaxial electrospinning method, determining their antimicrobial properties, and examining release profiles of OLE from these coaxial nanofibers. Optimum electrospinning process and solution parameters were determined to obtain uniform and bead-free coaxial nanofibers. Scanning electron microscopy and transmission electron microscopy (TEM) were used to characterize the morphology of the nanofibers. The antimicrobial activities of nanofibers were tested according to AATCC test method 100. Total phenolic content and total antioxidant activity were tested using in vitro batch release system. The quality and quantity of released components of OLE were determined by high-performance liquid chromatography. The changes in nanofibers were examined by Fourier-transform infrared spectroscopy. Uniform and bead-free nanofibers were produced successfully. TEM images confirmed the coaxial structure. OLE-loaded nanofibers demonstrated almost perfect antibacterial activities against both of gram-negative and gram-positive bacteria. Antifungal activity against C. albicans was rather poor. After a release period of 1 month, it was observed that ∼70-95% of the OLE was released from nanofibers and it was still bioactive. Overall results indicate that the resultant shell/core nanofibers have a great potential to be used as biomaterials.Article Citation - WoS: 48Citation - Scopus: 58Micro-Encapsulation of Ozonated Red Pepper Seed Oil With Antimicrobial Activity and Application To Nonwoven Fabric(John Wiley and Sons Inc., 2013) Özyıldız, Figen; Karagönlü, S.; Başal, Güldemet; Uzel, Ataç; Bayraktar, OğuzIn recent years, functional fabrics possessing antimicrobial activity have drawn significant interest because antibiotic resistance is becoming widespread among pathogenic micro-organisms. The aim of this study was to produce microcapsules incorporating ozonated red pepper seed oil (ORPSO) with antimicrobial properties and apply them to nonwoven fabrics to prepare functional textiles. Red pepper seed oil (RPSO) was ozonated and micro-encapsulated via a complex coacervation method using gelatin (GE) and gum arabic (GA) as wall materials. While micro-encapsulation yield and oil loading decreased with increases in the amount of surfactant, the mean particle size increased. The antimicrobial activity of the oil was tested via the disc diffusion method. The microcapsules were also tested using the agar well method. While RPSO had no effect on the test micro-organisms, the ORPSO and microcapsules containing ORPSO were found to be active against the test micro-organisms. The microcapsules were then applied to nonwoven fabric using the padding method to produce a disposable functional textile. The microcapsule-impregnated functional fabrics provided a 5 log decrease in 1 h. It is therefore possible to functionalize nonwoven fabrics to have antimicrobial activity against antibiotic-resistant micro-organisms, using microcapsules containing ORPSO.Article Citation - WoS: 66Citation - Scopus: 82Antimicrobial and Antioxidant Activities of Turkish Extra Virgin Olive Oils(American Chemical Society, 2010) Karaosmanoğlu, Hande; Soyer, Ferda; Özen, Banu; Tokatlı, FigenTurkish extra virgin olive oils (EVOO) from different varieties/ geographical origins and their phenolic compounds were investigated in terms of their antimicrobial and antioxidant properties in comparison to refined olive, hazelnut, and canola oils. Antimicrobial activity was tested against three foodborne pathogenic bacteria, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Enteritidis. Although all EVOOs showed a bactericidal effect, the individual phenolic compounds demonstrated only slight antimicrobial activity. Moreover, refined oil samples did not show any antimicrobial activity. Among the phenolic compounds, cinnamic acid (2 mg/kg of oil) had the highest percent inhibition value with 0.25 log reduction against L. monocytogenes. The synergistic interactions of tyrosol, vanillin, vanillic, and cinnamic acids were also observed against Salmonella Enteritidis. The antioxidant activities of oils were tested by β-carotene-linoleate model system and ABTS method. In both methods, EVOOs showed higher antioxidant activities, whereas refined oils had lower activity. The ABTS method provided a higher correlation (0.89) with total phenol content. © 2010 American Chemical Society.