TR Dizin İndeksli Yayınlar Koleksiyonu / TR Dizin Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14365/4
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Article Porphyridium Cruentum as a Biological Component for the Green Synthesis of Metal Nanoparticles and for the Evaluation of Their Antimicrobial Activity(Field Crops Central Research Institute, 2025-08-21) Mutaf, Tugce; Çalışkan, Gülizar; Oncel, Suphi; Elibol, Murat; Mutaf-Kilic, TugceSilver nanoparticles are an alternative to new-generation antimicrobial agents with their antimicrobial activity. Iron and zinc nanoparticles can potentially be used as UV protection in various applications. Nowadays, green synthesis of nanoparticles as a sustainable alternative attracts attention. Microalgae are promising in nanoparticle synthesis among biological sources due to their high biomass productivity and heavy metal accumulation ability. The present study aimed to investigate the potential of synthesizing intracellular silver, zinc and iron nanoparticles from Porphyridium cruentum microalgae. For nanoparticle synthesis, the effects of metal solution concentration and amount of biomass on particle size were investigated. The nanoparticles were characterized by dynamic light scattering, UV-vis spectrophotometry, and antimicrobial activity test. Silver nanoparticles of 169.7 nm, zinc nanoparticles of 189 nm, and iron nanoparticles of 356.7 nm were characterized by DLS. 169.7 nm silver nanoparticles were synthesized with 9.83 mM AgNO3 concentration and 0.19 mg/ml biomass: metal solution mixing ratio. The surface plasmon resonance band of silver nanoparticles was observed in the 300-350 nm wavelength range. According to the antibacterial activity results of silver nanoparticles, inhibition zone diameters were obtained as 10.83±0.76 mm and 11.33±0.57 mm against Escherichia coli and Staphylococcus aureus bacteria, respectively.Article Flia-Dependent Surface Macromolecules Promote Initial Biofilm Development of Escherichia Coli by Influencing the Bacterial Surface Properties(2023-03-31) Gördeşli Duatepe, Fatma Pınar; Duatepe, Fatma Pinar GordesliFliA is an important regulatory component for the synthesis of surface macromolecules which are involved in motility and biofilm development of Escherichia coli. In this study, the roles of FliA-dependent surface macromolecules in E. coli surface tension, sur- face heterogeneity and surface roughness, and initial biofilm development consisting of re- versible and irreversible adhesion were investigated using E. coli MG1655 wild-type strain and fliA gene deleted mutant strain. Negative Gibbs free energy change values calculated using bacterial surface tensions obtained by a spectrophotometric method showed that both wild-type and mutant cells in water can reversibly adhere to the surface of the model solid, silicon nitride (Si3N4). The calculations further showed that bacterial reversible auto- adhesion and co-adhesion were also thermodynamically favorable. In comparison, the re- versible adhesion and auto-adhesion capacities of wild-type cells were higher than the mu- tant cells. Direct measurements by atomic force microscopy (AFM) and thorough analysis of the recorded adhesion data showed that the irreversible adhesion strength of wild-type cells to Si3N4 in water was at least 2.0-fold greater than that of the mutants due to signifi- cantly higher surface heterogeneity resulting in higher surface roughness for the wild-type cells compared to those obtained for the mutants. These results suggest that strategies aimed at preventing E. coli biofilm development should also consider a combined method, such as modifying the surface of interest with a bacterial repellent layer and targeting the FliA and FliA-dependent surface macromolecules to reduce both reversible and irreversible bacterial adhesion and hence the initial biofilm development of E. coli.Article Citation - WoS: 3Metal Nanopartiküllerin Mikroalgler Aracılığı ile Yeşil Sentezi(Ege Univ, FAC Fisheries, 2023-03-15) Mutaf, Tuğçe; Çalışkan Bilgin, Gülizar; Öncel, Suphi; Elibol, Murat; Caliskan, GulizarYeşil sentez olarak adlandırılan, nanopartiküllerin biyolojik kaynaklar aracılığı ile sentezlenmesine olan ilgi son yıllarda artış göstermiştir. Bunun temel nedeni geleneksel yöntemler olan fiziksel ve kimyasal yöntemlerde indirgeyici ve stabilize edici ajanlar olarak yüksek miktarlarda toksik kimyasala ihtiyaç duyuluyor olmasıdır. Daha çevre dostu ve insan sağlığı için tehdit oluşturmayan bitki, fungus, bakteri, alg gibi organizmalar yeşil nanopartikül sentezi için alternatif kaynaklardır. Sucul mikroorganizmalar olan mikroalgler üretmiş oldukları proteinler, vitaminler, pigmentler, yağ asitleri, hücre içi- hücre dışı polisakkaritler gibi fonksiyonel özelliğe sahip metabolitler sayesinde uzun yıllardır gıda, kozmetik ve ilaç endüstrilerinde formülasyonlara eklenmektedir. Bunların yanı sıra, son yıllarda yapılan çalışmalarla nanopartikül sentezinde de yüksek potansiyele sahip oldukları görülmüştür. Özellikle metal iyonlarının depolanmasını ve detoksifikasyonunu yapabildiklerinden ve metal iyonlarını elementel hale indirgeyen hücre içi ve hücre dışı metabolitlerce zengin olduklarından, metal nanopartiküllerin sentezi için yüksek potansiyele sahiptirler. Son yıllarda mikroalglerden nanopartikül sentezine odaklanmış olan yayın sayısı artmış ve pek çok mikroalg türünün gümüş, altın, titanyum, çinko, demir vb. metal nanopartikülleri hücre içi ve hücre dışı yollarla sentezleme potansiyeli araştırılmıştır. Bu derleme makale kapsamında, nanopartikül sentezi için çalışılmış olan mikroalg ve siyanobakteri türleri, kullanılan farklı sentez yöntemleri, nanopartiküllerin sentez mekanizması, temel karakterizasyon yöntemleri ve yeşil sentezle üretilen nanopartiküllerin antimikrobiyal aktivitelerine odaklanılmıştırArticle Production of Value-Added Bioproducts Using a Modified Continuous Biofilm Reactor by Citrobacter Freundii Dsm 15979(2021-03-31) Güngörmüşler, MineThe present paper reports the results of Citrobacter freundii, strain DSM 15979, that was tested for its ability to produce value added chemicals from biodiesel derived glycerol in a mesophilic fluidized bed biofilm reactor operating under continuous conditions at a specified hydraulic retention time (HRT) at 30°C. Elevating feed concentrations (10 to 144 g/L) were tested in order to understand their effects on simultaneous production of value added products with immobilized whole cells. Gin was found to be a significant independent variable for the productions of 1,3-PDO, 2,3-BD, ethanol, acetic, succinic and lactic acids under different organic loading rates (OLR). The major metabolite in the metabolic pathway was found to be 1,3-PDO followed by 2,3-BD reaching the maximum values as 26.1 and 18.8 g/L under the conditions of 92 g/L crude glycerol and 8 h, which is represents an OLR of 11.5 g/L.h, suggesting the formation of biofilms favor the utilization of high substrate concentration to enhance the mixed fermentation.