Yazar "Camas, Mustafa" seçeneğine göre listele

Listeleniyor 1 - 4 / 4
  • [ X ]
    Öğe
    Biosynthesis of gold nanoparticles using marine bacteria and Box-Behnken design optimization
    (Taylor & Francis Inc, 2019) Camas, Mustafa; Celik, Fatih; Camas, Anil Sazak; Ozalp, Hasan Baris
    Gold nanoparticles are exciting materials because of their potential applications in optics, electronics, biomedical, and pharmaceutical fields. In recent years, environmentally friendly, low-cost biosynthesis methods with bio-applicable features have continued to be developed for the synthesis of gold nanoparticles. In the present study, an actinobacterial strain was isolated from the Petrosia ficiformis (Poiret 1798) sponge, which was collected from a marine environment, and the gold nanoparticle synthesis was performed for the first time from the bacteria type belonging to the Citricoccus genus. The synthesis conditions were optimized using the Box-Behnken experimental design, with a statistical method that included three independent variables (temperature, time, and mixture ratio) to affect the synthesis at three levels (+1, 0, and -1). Accordingly, the conditions proposed for the biosynthesis of gold nanoparticles at the maximum optical density values that are specific for the Citricoccus sp. K1D109 strain were estimated as 35 degrees C temperature, 24 h, and 1/5 mixture ratio (cell-free extract/HAuCl4 center dot 3H(2)O). When recommended conditions were applied, it was determined that the maximum absorbance of the synthesized gold nanoparticles is 1.258 at 545 nm, and their sizes are in the range of 25-65 nm, according to transmission electron microscopy (TEM) data.
  • [ X ]
    Öğe
    Chronic exposure of tilapia (Oreochromis niloticus) to iron oxide nanoparticles: Effects of particle morphology on accumulation, elimination, hematology and immune responses
    (Elsevier Science Bv, 2016) Ates, Mehmet; Demir, Veysel; Arslan, Zikri; Kaya, Hasan; Yılmaz, Sevdan; Camas, Mustafa
    Effects of chronic exposure to alpha and gamma iron oxide nanoparticles (alpha-Fe2O3 and gamma-Fe2O3 NPs) were investigated through exposure of tilapia (Oreochromis niloticus) to 0.1, 0.5 and 1.0 mg/L (9.2 x 10(-4), 4.6 x 10(-3) and 9.2 x 10(-3) mM) aqueous suspensions for 60 days. Fish were then transferred to NP-free freshwater and allowed to eliminate ingested NPs for 30 days. The organs, including gills, liver, kidney, intestine, brain, spleen, and muscle tissue of the fish were analyzed to determine the accumulation, physiological distribution and elimination of the Fe2O3 NPs. Largest accumulation occurred in spleen followed by intestine, kidney, liver, gills, brain and muscle tissue. Fish exposed to gamma-Fe2O3 NPs possessed significantly higher Fe in all organs. Accumulation in spleen was fast and independent of NP concentration reaching to maximum levels by the end of the first sampling period (30th day). Dissolved Fe levels in water were very negligible ranging at 4-6 mu g/L for alpha-Fe2O3 and 17-21 mu g/L for gamma-Fe2O3 NPs (for 1 mg/L suspensions). Despite that, Fe levels in gills and brain reflect more dissolved Fe accumulation from metastable gamma-Fe2O3 polymorph. Ingested NPs cleared from the organs completely within 30-day elimination period, except the liver and spleen. Liver contained about 31% of alpha- and 46% of gamma-Fe2O3, while spleen retained about 62% of alpha- and 35% of the gamma-polymorph. No significant disturbances were observed in hematological parameters, including hemoglobin, hematocrit, red blood cell and white blood cell counts (p > 0.05). Serum glucose (GLU) levels decreased in treatments exposed to 1.0 mg/L of gamma-Fe2O3 NPs at day 30 (p < 0.05). In contrast, GLU levels increased during the elimination period for 1.0 mg/L alpha-Fe2O3 NPs treatments (p < 0.05). Transient increases occurred in glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and lactate dehydrogenase (LDH). Serum Fe levels did not change during exposure (p > 0.05), but increased significantly within elimination period due to mobilization of ingested NPs from liver and spleen to blood. Though respiratory burst activity was not affected (p > 0.05), lysozyme activity (LA) was suppressed suggesting an immunosuppressive effects from both Fe2O3 NPs (p < 0.05). In contrast, myeloperoxidase (MPO) levels increased significantly in treatments exposed to alpha-Fe2O3 NPs (p < 0.05), and the effect from gamma-polymorph was marginal (p > 0.05). The results indicate that morphological differences of Fe2O3 NPs could induce differential uptake, assimilation and immunotoxic effects on O. niloticus under chronic exposure. (C) 2016 Elsevier B.V. All rights reserved.
  • [ X ]
    Öğe
    Sarcotragus foetidus (Schmidt, 1862) Denizel Süngeri ile Uranyum (VI) Biyosorpsiyonunun Merkezi Kompozit Dizayn ile İstatistiksel Olarak Araştırılması
    (2016) Çelik, Fatih; Camas, Mustafa; Camas, Anil Sazak; Özalp, Hasan Barış
    Mikroorganizmalar ve biyolojik materyaller kullanarak radyonüklitlerin, ağır metallerin, toryum ve uranyum gibi radyoaktif metallerin sulu çözeltilerden geri alınması veya uzaklaştırılması üzerine birçok çalışma vardır. Bu çalışmada, Sarcotragus foetidus (Schmidt, 1862) olarak adlandırılan deniz süngerinin sulu çözeltilerden uranyum alımı istatistiksel olarak araştırıldı. S. foetidus (Schmidt, 1862) deniz süngeri örnekleri Babakale (Ayvacık / Çanakkale) açıklarından toplandı. Uranyum (VI) geri alım denemeleri kesikli yöntem ile gerçekleştirildi. Biyosorpsiyonu etkileyen parametreler Merkezi Kompozit Deneysel Tasarımı (CCD) kullanılarak analiz edildi. Bu çalışma için; pH, sıcaklık, temas süresi ve uranyum başlangıç konsantrasyonu gibi dört bağımsız değişken seçildi. Ana parametrelerden pH, temas süresi ve uranyum başlangıç konsantrasyonu biyosorpsiyon prosesinde istatistiksel olarak anlamlı olarak kabul edildi. Diğer bir yandan; biyosorpsiyon işlemi üzerinde, pH- temas süresi, pH - uranyum başlangıç konsantrasyonu gibi ikili etkileşimler önemli parametreler olarak belirlendi. Biyosorbsiyon prosesinin optimum koşulları; pH:4, sıcaklık: 38 , uranyum başlangıç konsantrasyonu: 20 mg/L ve temas süresi: 31 dakika olarak hesaplandı. Bu koşullar altında biyosorpsiyon verimi % 93.29±2 olarak elde edildi
  • [ X ]
    Öğe
    Uranium (VI) Biosorption on Marine Sponge, Sarcotragus foetidus (Schmidt, 1862) and Its Statistical Investigation Using Central Composite Design
    (Central Fisheries Research Inst, 2016) Celik, Fatih; Camas, Mustafa; Camas, Anil Sazak; Ozalp, Hasan Baris
    The biosorption of heavy metals, radionuclides, uranium and thorium for the recovery or removal from aqueous systems using various micro-organisms and biological substances has been investigated by several groups of workers. In this paper, the uptake of uranium (VI) from aqueous systems by a marine sponge, Sarcotragus foetidus (Schmidt, 1862) has been investigated. S. foetidus samples were collected from Babakale/Ayvacik/Canakkale in Turkey. Uranium (VI) uptake experiments were carried out by the batch technique. The affecting parameters were analyzed using Central Composite Design (CCD) as the experimental method. Four independent variables such-pH, temperature, contact time, and initial uranium concentration were selected for this study. The influences of initial pH, contact time, and initial uranium concentration on the biosorption process were considered statistically significant as main effects. On the other hand, interaction effects of pH and contact time, as well as pH and initial uranium concentration, were considered as significant parameters on the biosorption process. The optimum condition of biosorption process was found to be at initial pH: 4, temperature: 35 degrees C, initial uranium concentration: 20 mg/L, and contact time: 31 minutes. At these conditions, the biosorption yield of uranium (VI) ions was obtained to be 93.29 +/- 2%.