Browsing by Author "Yildirim, Ayfer"

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Adsorption Performance of bacillus Licheniformis Sp. Bacteria Isolated From the Soil of the Tigris River on Mercury in Aqueous Solutions
(Taylor & Francis Ltd, 2022) Acay, Hilal; Keskin, Cumali; Acay, Hilal; Keskin, Cumali; Aygun, Husamettin
Mercury is known to be one of the most toxic heavy metals in the environment and is released into the water systems in significant quantities through natural events and industrial process activities. Many chemical materials are used as adsorbents in the removal of toxic metals from the environment and wastewaters. However, using microorganisms as bio-sorbents instead of chemical materials has become common recently due to their low cost, easy availability and presence in nature. In this study, Bacillus licheniformis in the soil isolated from the Tigris River was used as bio-sorbent. The mercury (Hg(II)) absorption behaviour of Bacillus licheniformis bacteria (BLB) was investigated using inductively coupled plasma mass spectrometry. The effects of equilibrium of adsorption time, temperature, adsorbent dosage and pH on the adsorption of Hg (II) onto BLB were determined. The maximum adsorption capacity of Hg (II) onto BLB was determined as 82.12 mg/g (T = 25 degrees C, pH 5, Co = 50 mg/L, m = 25 mg). The BLB was characterised using Fourier transform infrared spectroscopy analysis, thermal gravimetric analysis/differential thermal analysis, scanning electron microscopy analysis and energy-dispersive X-ray spectroscopy analysis. In addition, pseudo-first-order and pseudo-second-order kinetic models were applied. The equilibrium data for the adsorption of Hg(II) onto BLB were examined by the Langmuir and Freundlich isotherm models. The activation energy was calculated using the pseudo-second-order rate constant. These results suggested the BLB can be used as an efficient adsorbent for the removal of Hg(II) metal ions from wastewater. When the results of bio-sorption studies were examined, it was found that the bio-sorbent could be reused easily. The present study suggests that microorganism bio-sorbents are useful for the efficient removal of mercury from aqueous solutions.
Green Synthesis of pleurotus Eryngii-derived Nanomaterials for Phytopathogen Control
(Wiley-v C H verlag Gmbh, 2024) Acay, Hilal; Guney, Inci Guler; Yildirim, Ayfer; Dervis, Sibel; Dereli, Elif
Growing concerns over the human health and environmental impacts of conventional fungicides, coupled with the escalating challenge of microbial resistance, have fueled the search for sustainable biocontrol strategies against plant pathogens. This study reports, for the first time, the green synthesis and characterization of a novel, eco-friendly nanomaterial, designated Pleurotus eryngii-Lecithin-Chitosan Nanomaterial (PEELCN), derived from P. eryngii extract (PEE), lecithin (L), and chitosan (C). The structural attributes of PEELCN were elucidated using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), X-ray Diffraction (XRD), and zeta potential measurements, confirming the successful formation of a stable and uniform nanostructure. The antifungal activity of PEELCN, and PEE, was assessed against five economically important phytopathogenic fungi: Neoscytalidium dimidiatum, Alternaria alternata, Verticillium dahliae, Bipolaris sorokiniana, and Fusarium oxysporum. Both PEE and PEELCN exhibited significant inhibitory effects on the mycelial growth of V. dahliae, B. sorokiniana, and N. dimidiatum, with varying degrees of efficacy. The differential antifungal activity suggests a species-specific mode of action. The findings highlight the promising potential of PEELCN as a sustainable, biocompatible, and cost-effective nanofungicide for the management of plant diseases, with the potential for development into a commercially viable biofungicide for sustainable agriculture.
Kinetic, Equilibrium and Thermodynamic Investigations for the Bio-Sorption of Dyes Onto Crosslinkedpleurotus Ostreatus-based Bio-Composite
(Taylor & Francis Ltd, 2022) Yildirim, Ayfer
Water pollution due to dyes has a significant impact on the environment and causes unfavourable risks for human health. This study aimed to synthesise a crosslinkedPleurotus ostreatus-based bio-composite as an efficient low cost biosorbent and investigate its bio-sorption performance for dyes via kinetic, isotherm and thermodynamic parameters. The characterisation of the bio-composite was determined by Fourier transform infrared spectrophotometer, field-emission scanning electron microscopy, differential scanning calorimetry and X-ray diffraction. Two reflections peaks, 2 theta = 13 degrees and 21 degrees, were revealed in the X-ray diffraction pattern of the bio-composite. The effects of contact time, pH and initial dye concentration were investigated as the physical-chemical parameters. The neutral pH was found as an optimum pH for dyes. The reuse test revealed that the bio-sorbent was capable of using 5 times for dyes. The pseudo-first order and pseudo-second order kinetic models were applied to determine the mechanism of the adsorption process. The isotherm investigation was conducted using the Langmuir and Freundlich isotherm models. The experimental data was determined to be in the good agreement with the pseudo-second-order model and Langmuir isotherm model. The maximum adsorption capacity was measured to be 77.11 and 40.11 mg/g for the bio-sorption of malachite green and methylene blue, respectively. The thermodynamic studies of the bio-sorption showed that the adsorption process was a spontaneous endothermic process and that disorder increased during the process. This study indicated that the synthesised bio-sorbent could be used as an eco-friendly, cost-effective and recyclable bio-composite for the bio-sorption of dyes from aqueous solution.
Morchella esculenta-based chitosan bionanocomposites: Evaluation as an antifungal agent
(Wiley Online Library, 2022) Acay, Hilal; Derviş, Sibel; Güney, İnci Güler; Derviş, Sibel
Considering the damage caused by fungicides to human health and problems such as microbial resistance, biological control against plant pathogens has started to gain importance worldwide. This research demonstrates a new, simple, cost-effective, and environmentally friendly method for synthesizing chitosan bionanocomposite (CBNC) from Morchella esculenta (L) Pers-extract (MEE). The antifungal property of the synthesized Morchella esculenta (L) Pers-chitosan bionanocomposite (MCBNC) against some plant pathogens was also evaluated. FTIR, XRD, FE-SEM, DSC, TGA, and BET were used to characterize the synthesized MCBNC. Mushroom-based chitosan nanoparticles were evaluated for antifungal activity against some fungal pathogens, including Neoscytalidium novaehollandiae, N. dimidiatum, Alternaria alternata, Verticillium dahliae, Bipolaris sorokiniana, and Colletotrichum sp. The findings obtained clearly showed that chitosan nanoparticles have antifungal activity. The results suggest that the chitosan nanoparticle can be used in the field to protect various crops from phytopathogens. Novelty impact statement Chitosan bionanocomposite (MCBNC) synthesis was performed for the first time using the wild mushroom Morchella esculenta, which has strong bioactive properties. It was observed that the bionanomaterial, which was characterized by FTIR, XRD, FE-SEM, DSC, TGA, and BET analyses, has high antifungal activity against plant pathogens such as Alternaria alternata and Bipolaris sorokiniana. MCBNCs synthesized by the green synthesis method can be an important area of use in the fight against plant pathogens, which corresponds to 1/3 of the world's agricultural production potential.
Synthesis and Characterisation of Mushroom-Based Nanocomposite and Its Efficiency on Dye Biosorption Via Antimicrobial Activity
(Taylor & Francis Ltd, 2022) Acay, Hilal; Acay, Hilal; Baran, Firat
Mushrooms are highly effective for biotechnological products and economically. Mushroom-based nanocomposites occasionally used in recent studies. Pleurotus ostreatus (PO) from southeast Turkey that used in our work is the most commonly present cultivated white-rot edible fungus all around the world. Until now, no report is existing on the biosorption study of Reactive orange 16 (RO16) with mushroom-based nanocomposite. Therefore, the main goal of this work was to synthesise Pleurotus ostreatus-based-chitosan (POCN) nanocomposite and characterise via Fourier transform infrared spectrophotometer, Differential scanning calorimetry, Field-emission scanning electron microscopy, Brunauer-Emmett-teller, and X-ray diffraction techniques; investigate the antimicrobial activity and adsorption behaviour for removal of RO16 dye. The adsorption of RO16 by batch technique was evaluated with pH, initial dye concentration and temperature effect. Point of zero charge was evaluated. The adsorption of dye followed by the pseudo-second-order kinetic model and data of equilibrium was well fitted with the Langmuir isotherm model. The maximum adsorption capacity of POCN for RO16 was found as 65.5 mg/g (initial dye concentration: 100 mg/g, temperature: 298 K). Besides, POCN was researched for antimicrobial activity against some pathogens such as Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 11774 standard bacterial strains and Candida albicans ATCC 10231 fungal strain by using microdilution method on the Minimum Inhibiting Concentration (MIC). Furthermore, during four cycles of adsorption and desorption, regeneration experiment revealed good reusability of POCN nanocomposite with 0.1 M HCl as a desorbing agent.