İlgi alanları

• MakaleYalnız künye2026/r/bayburt/12687
  Physical, chemical and thermal characterization of bacterial nanocellulose produced using sugar beet molasses by Komagataeibacter sp. SB2569

  Kara, Adem; Bayram, Sinan

  Bacterial nanocellulose (BNC) is a biopolymer synthesized by bacteria utilizing various carbon sources. The biocompatible and biodegradable nature of BNC offers considerable advantages for its application in fields such as medicine, biomedical engineering, cosmetics, food, nanocomposites, and organoelectronics. Nevertheless, the high production costs necessitate the development of more cost-effective and efficient BNC production methodologies. This study aimed to produce BNC utilizing cost-effective sugar beet molasses. To achieve this, bacteria isolated from various vinegar samples were assessed, revealing that the BNC production potential of these isolates ranged from 2.09 to 3.21 g L⁻1. The 16S rDNA gene of the strain with the highest BNC yield was amplified and sequenced, and it was subsequently deposited in the GenBank database as Komagataeibacter sp. SB2569, with the accession number PV231799.1. XRD analysis revealed characteristic diffraction peaks at 14.8°, 16.5°, 22.6°, and 34.5°, confirming the cellulose 1β crystalline structure and high crystallinity of the synthesized BNC. FTIR analysis exhibited characteristic absorption bandsthat, confirming the presence of β-1,4-glycosidic linkages and the cellulose I structure of BNC. TGA analysis showed an initial weight loss of ~ 5% between 0–100 °C, a major degradation of ~ 75% occurring at 220–350 °C with a maximum decomposition rate at 343 °C, and a residual mass of approximately 10–20% remaining above 600 °C. The findings indicate that the Komagataeibacter sp. SB2569 strain holds significant potential for BNC production using low-cost carbon sources.

  AtıfScopus1·WoS1

  İncele
• MakaleYalnız künye2026/r/bayburt/12641
  Molecularly engineered bacterial biopolymer as multifunctional interfacial regulators for dendrite-free and stable aqueous zinc-ion batteries

  Adhami, Sadaf; Bayram, Sinan; Coskun, Sahin; Sonmezoglu, Savas; Yuksel, Recep

  Aqueous zinc-ion batteries (ZIBs) are promising candidates for next-generation energy storage owing to their intrinsic safety, low cost, and high theoretical capacity. However, their practical application remains hindered by dendrite formation and parasitic side reactions such as hydrogen evolution reaction (HER), anode corrosion, and passivation. Herein, we introduce a sustainable and scalable strategy based on a bacterial eumelanin biopolymer (S2–20), synthesized via the oxidative metabolism of Pseudomonas aeruginosa with indole derivatives, and directly deposited onto Zn foil via spin coating. The S2–20 biopolymer provides a conformal, ion-permeable interface that simultaneously guides uniform Zn nucleation, enhances electrolyte wettability, and suppresses parasitic side reactions. Symmetric cells demonstrate significantly increased Zn2+ transference number (0.908), and prolonged cycling stability exceeding 1200 h at 1.0 mA cm−2 and 200 h under harsh conditions up to 20 mA cm−2. Full cells with V2O5 cathodes further confirm remarkable specific capacity (374 mAh g−1 at 1.0 A g−1) and capacity retention, maintaining 150.5 mAh g−1 after 2200 cycles at 1.0 A g−1. This work presents the first demonstration of a bacterial eumelanin biopolymer as a multifunctional interfacial stabilizer for Zn metal, offering a truly green, cost-effective, and scalable pathway toward safe and sustainable aqueous ZIBs.

  İncele
• MakaleYayıncıda açık erişim2026/r/bayburt/11412
  Investigation of structural, optical and optoelectronic properties of eumelanin pigment

  Aksoy Pehlivanoglu, Seval; Bayram, Sinan

  In this work, the structural, morphological and optical properties of the eumelanin film fabricated on an FTO substrate were first investigated. Then, the effects of illumination intensitiy on the optoelectronic properties of the device fabricated on p-Si substrate (Eumelanin/p-Si) were investigated. The deposited film was identified as polycrystalline from the XRD pattern. The crystallite size was found to be approximately 13 nm. Surface morphology analysis of the film was carried out using atomic force microscopy (AFM) measurements. The surface roughness value (Rq) of the film was determined to be 55.7 nm. The film’s transmittance in the visible region is approximately 83%. The average refractive index in the visible region was calculated to be 1.39. The value of the eumelanin film was determined using both the Tauc technique and the Kubelka-Munk function. The direct and indirect optical bandgaps of eumelanin were calculated using both the Tauc method and the Kubelka-Munk function. The calculated direct and indirect optical bandgap values are, respectively, 2.79 eV and 1.96 eV for the Tauc method, and 2.65 eV and 1.79 eV for the Kubelka-Munk method. The electronic parameters of Eumelanin/p-Si heterostructure were derived from its characteristics. The charge transport mechanisms controlling the diode behavior of the eumelanin/p-Si structure were investigated and analyzed using the power law relationship. measurements performed at various illumination intensities indicated that the device exhibited photoconductive behavior. All the results obtained from this study demonstrate the potential of eumelanin/p-Si device to be used in photonic applications.

  İncele
• MakaleYayıncıda açık erişim2026/r/bayburt/11141
  Determination of Biological Activities of Encapsulated Bee Venom

  Keskİn, Şaban; Bayram, Sinan; Keskİn, Merve

  Bee venom is an important bee product used directly in apitherapy applications. Once harvested, bee venom crystallizes rapidly upon contact with air. Furthermore, bee venom that is not produced and stored under optimal conditions deteriorates rapidly. For this reason, there is a need for new methods that can extend the shelf life of bee venom. Encapsulation techniques are widely used to extend the shelf life of bioactive components by immobilizing them within a biocompatible biopolymer. In this study, the potential of encapsulating bee venom using ionic gelation with chitosan, a biocompatible polymer, was investigated. It was found that chitosan had a 91% encapsulation efficiency for bee venom. It has been determined that bee venom inhibits the acetylcholinesterase enzyme by 84%±2.1, whilst its total protein content is 64.2%±1.8. The antimicrobial activity of the encapsulated bee venom was evaluated against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis. The inhibition zones ranged from 11 to 12 mm. The results showed that the encapsulated bee venom retained its biological activity without significant loss.

  İncele
• MakaleYayıncıda açık erişim2026/r/bayburt/11039
  Deep Eutectic Solvents as Sustainable Media for Efficient Recovery of Phenolics From Black (Lycium ruthenicum Murr.) and Red (Lycium barbarum Lam.) Goji Berries: Optimization and Functional Evaluation

  Gerçek, Yusuf Can; Kutlu, Naciye; Çelik, Saffet; Bayram, Sinan; Çevik, Berke; Baştürk, Fatma Nur; Özmener, Bahar; Ecem Bayram, Nesrin

  Deep eutectic solvents (DESs) have been frequently preferred over the past decade as alternatives to conventional solvents for the extraction of bioactive compounds from natural products. Meanwhile, black and red goji berries are widely consumed as functional foods due to their many functional properties reported in the literature. The aim of this study is to evaluate the effectiveness of different DESs in the extraction of individual phenolic compounds from goji berry (Lycium barbarum and L. ruthenicum) fruits, to determine the most suitable DES, and to optimize the extraction conditions. The DES that provided the highest yield in the extraction of individual phenolic compounds from L. barbarum was determined to be proline:citric acid (DES6 – a total of approximately 33,545 µg/kg), while for L. ruthenicum it was choline chloride:acetic acid (DES3 – a total of approximately 37,496 µg/kg). Rutin was the predominant phenolic compound in both species. DESs provided a higher phenolic yield compared to ethanol and water. In addition, L. ruthenicum exhibited higher total phenolics, flavonoids, proanthocyanidins, and antioxidant activity compared to L. barbarum. These findings reveal that DESs are a green, efficient, and sustainable alternative for the extraction of phenolic compounds from goji berries.

  AtıfScopus1·WoS1

  İncele
• MakaleYalnız künye2025/r/bayburt/12645
  Optimized ultrasonic-NaDES extraction of anthocyanins, polyphenolics, and organic acids from chokeberry fruit with blueness and antimicrobial evaluation

  Gerçek, Yusuf Can; Kutlu, Naciye; Çelik, Saffet; Bayram, Sinan; Kırkıncı, Seran; Ecem Bayram, Nesrin

  Deep eutectic solvents (DESs) have been widely used in food processing in recent years, owing to their remarkable advantages. The aim of this study was to evaluate the potential of DESs for the recovery of bioactive components from chokeberry fruit. First, among the 10 different DESs, the DES that extracted the highest total individual phenolic content (TIPC) from chokeberry was determined. Then, ultrasonically assisted extraction conditions (ultrasonic amplitude, time, and temperature) were optimized by response surface methodology to obtain the maximum amount of TIPC using this DES. According to the results obtained, the natural deep eutectic solvent (NaDES) choline chloride: acetic acid (1:2, 30% water content) provided the highest yield for TIPC extraction and the optimum conditions for maximum TIPC extraction were determined as 100% for ultrasonic amplitude, 50 °C for temperature and 60 min for sonication time. The TIPC content of the extracts prepared with this NaDES was determined between 1740.26 and 3703.14 mg/kg. In addition, the individual organic acid and individual anthocyanin contents of the NaDES extracts, as well as their antioxidant and antimicrobial activities, were determined. Chlorogenic acid (1392.351–2361.48 mg/kg) among phenolic compounds, pyruvic acid (9361.35–47398.04 mg/kg) among organic acids and kuromanin chloride (69748.13–134668.24 mg/kg) among anthocyanins were the dominant compounds in NaDES extracts. However, the extracts showed varying levels of antimicrobial activity against Gram (+) bacteria, Gram (−) bacteria, and yeast-like fungi (Candida strains). Finally, the Blue Applicability Grade Index (BAGI) was used to evaluate the practicality/blueness potential of the chromatographic method used to determine the anthocyanin composition of the DES extracts. In conclusion, NaDES (choline chloride:acetic acid) can be an alternative solvent for the recovery of some individual phenolics, organic acids and anthocyanins under different extraction conditions. In addition, the use of NaDES in the recovery of various functional compounds needed in food, cosmetics, pharmaceuticals, etc., is important for the promotion of sustainability and green technology.

  AtıfScopus19·WoS18

  İncele
• MakaleYayıncıda açık erişim2025/r/bayburt/10931
  Electrospinning Encapsulation of Chlorophylls Microwave-Extracted from Spinach Waste and Utilization as Coloring Agent in Yogurt

  Isik, Beyza Sukran; Bayram, Sinan; Altay, Filiz

  Natural colorants have become a developing market because of consumer preferences, and more cost-effective and stable production is necessary. In the present study, a natural green colorant was obtained via microwave-assisted extraction from spinach waste to produce affordable, environmentally-friendly, and innovative colorants. The extracts were encapsulated with zein via uniaxial and coaxial electrospinning techniques to overcome the stability issues associated with their natural green color. The encapsulation efficiencies of uniaxially encapsulated chlorophyll extracted from spinach waste by microwave were 63.50 and 57.18 for chlorophyll a and b, respectively. The efficiencies of chlorophyll a and b by coaxial electrospinning were found 49.53% and 88.58%, respectively. The microwave-assisted extraction and the addition of eumelanin may contribute positively to the antioxidant activity and thermal stability of electrospun samples. The stability test against light revealed that 61% of chlorophyll a could be preserved by uniaxial electrospinning. In addition, when chlorophyll-loaded nanofibers were incorporated into yogurt, a more stable green color was achieved during storage.

  AtıfScopus10·WoS9

  İncele
• MakaleYalnız künye2024/r/bayburt/13093
  Ultrasonic assisted extraction of water-soluble vitamins from minor components of bee pollen with deep eutectic solvents (DESs) as green solvent

  Çelik, Saffet; Gerçek, Yusuf Can; Kutlu, Naciye; Bayram, Sinan; Kırkıncı, Seran; Ecem Bayram, Nesrin

  In this study, different deep eutectic solvents (DESs) were used for vitamin extraction from bee pollen. The DES combination with the highest total amount of individual vitamins was choline chloride: ethylene glycol (molar ratio 1:2). The response surface method was then used to optimize the extraction conditions. The independent variables used for optimization were ultrasonic power, time, and temperature, while the dependent variables were the total individual amino acids, total individual phenolic compounds, and total individual vitamin contents. Spectrophotometric analyses and antimicrobial activity were also determined in the extracts. In addition, AGREEprep, ComplexGAPI and BAGI tools were used to evaluate the greenness of the method. The results obtained with DES were compared with water, ethanol, and methanol extracts, which were considered control groups. As a result of optimization, the optimum conditions were found to be 75 % for ultrasonic power, 71.5 min for sonication time, and 40 °C for ultrasonic bath temperature. The model's composite desirability value (d) was found to be 0.81. The predicted value and the experimental values were close to each other. Furthermore, the most dominant vitamin in DES extracts was ascorbic acid, the most dominant amino acid was proline, and the most dominant phenolic compound was myricetin. The amounts of these compounds were higher than those obtained from water, ethanol, and methanol extracts. The spectrophotometric analysis results obtained higher yields with DES compared to the control groups. Antimicrobial activity analysis showed that pollen extracts prepared using choline chloride: ethylene glycol had a weak inhibitory effect for Gram-positive and Gram-negative bacteria but not yeast-like fungal strains. In conclusion, DES has been successfully used to extract vitamins and other bioactive compounds from bee pollen. The results obtained showed that DESs can be an alternative to organic solvents for the extraction of vitamins, which are among the minor components of bee pollen. Besides, the potential of the application different DESs for more efficient extraction of vitamins and components with important pharmaceutical properties from bee pollen needs to be evaluated in detail.

  AtıfScopus14·WoS12

  İncele
• MakaleYalnız künye2024/r/bayburt/12896
  Synthesis of flaxseed gum/melanin-based scaffold: A novel approach for nano-encapsulation of doxorubicin with enhanced anticancer activity

  Kumar, Deepak; Pal, Ravi Raj; Das, Neeladri; Roy, Partha; Saraf, Shubhini A.; Bayram, Sinan; Kundu, Patit P.

  Doxorubicin is a powerful chemotherapy medicine that is frequently used to treat cancer, but because of its extremely destructive side effects on other healthy cells, its applications have been severely constrained. With the aim of using lower therapeutic doses of doxorubicin while maintaining the same anti-cancerous activity as those of higher doses, the present study designs nano-encapsulation of doxorubicin by acrylamide grafted melanin as core and acrylic acid grafted flax seed gum as shell (DOX@AAM-g-ML/AA-g-FSG-NPs) for studies in-vivo and in-vitro anticancer activity. For biological studies, the cytotoxicity of DOX@AAM-g-ML/AA-g-FSG-NPs was examined on a cancerous human cell line (HCT-15) and it was observed that DOX@AAM-g-ML/AA-g-FSG-NPs exhibited very high toxicity towards HCT-15. In-vivo investigation in colon cancer-inflicted rat model also showed that DOX@AAM-g-ML/AA-g-FSG-NPs showed better anticancer activity against cancerous cells as compared to free doxorubicin. The drug release behavior of DOX@GML-GFS-NPs was studied at several pH and maximum drug release (95 %) was recorded at pH -7.2, and kinetic data of drug release was follows the Higuchi (R2 = 0.9706) kinetic model. Our study is focussed on reducing the side effects of doxorubicin by its nano-encapsulation in acrylamide grafted melanin as core and acrylic acid grafted flax seed gum that will also enhance its efficiency.

  AtıfScopus14·WoS14

  İncele
• MakaleYalnız künye2024/r/bayburt/11688
  An optimization study for amino acid extraction from bee bread using choline chloride-acetic acid deep eutectic solvent and determination of individual phenolic profile

  Kutlu, Naciye; Gerçek, Yusuf Can; Çelik, Saffet; Bayram, Sinan; Ecem Bayram, Nesrin

  In this study, the aim was to optimize the extraction conditions (molar ratio, time, temperature) in order to maximize the total individual amino acid (TAA) yield from bee bread, which is a fermented bee product, using choline chloride-acetic acid deep eutectic solvent (DES). In addition to the phenolic profile and amino acid profile investigated by LC-MS/MS, some spectrophotometric (total phenolic content, total flavonoid content, total proanthocyanidin content) and bioactivity (antioxidant/antimicrobial activity) tests were carried out on the extracts. Optimum conditions were determined as 1:2 for molar ratio, 15 min for time and 10 °C for temperature with optimization based on the TAA values of the different extracts (d: 0.99). Molar ratio and temperature were found to have statistically significant effects on TAA values. At optimum conditions, the amount of TAA obtained with DES (29.678 g/kg) was found to be approximately 35.2% and 54.4% higher than that obtained with ethanol and methanol extracts, respectively. All these results indicate that choline chloride-acetic acid DES can be chosen when preparing bee bread extracts, which are evaluated for different areas of use such as food and health due to active ingredient content. Higher active ingredients can be extracted by trying different DES combinations.

  AtıfScopus7·WoS9

  İncele