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Dive into the research topics where Ozfer Yesilada is active.

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Featured researches published by Ozfer Yesilada.


Process Biochemistry | 2003

Decolorization of textile dyes by fungal pellets

Ozfer Yesilada; Dilek Asma; Seval Cing

Decolorization of various dyes by pellets of white rot fungi was studied. All fungal pellets used could remove more than 75% of the color of these dyes in 24 h. Effect of various conditions such as initial pH, concentration of dye, amount of pellet, temperature and agitation on Astrazone blue dye decolorization activity of Funalia trogii was tested and the longevity of this decolorization activity under optimum conditions was investigated in repeated-batch mode. An increase in the amount of pellet positively affected the longevity of the decolorization activity while a decrease in dye decolorization capability of pellets occurred with increasing dye concentration in repeated-batch mode. Spectrophotometric and microscopic examinations of F. trogii pellets showed that the process involved decolorization through microbial metabolism but not biosorption. The effect of glucose concentration and cheese whey on longevity of decolorization activity was also tested. The percentage of decolorization at a dye concentration of 264 mg/l remained high after 10 days operation especially in culture media with cheese whey. This study showed that white rot fungal pellets could effectively be used as an alternative to the traditional physicochemical process.


Bioresource Technology | 2002

Decolourisation of the textile dye Astrazon Red FBL by Funalia trogii pellets.

Ozfer Yesilada; Seval Cing; Dilek Asma

The effects of various conditions such as initial pH, dye concentrations, amount of pellet, temperature and agitation on decolourising activity of Funalia trogii were investigated. These, except initial pH, were all found to be important for dye decolourising activity of F. trogii. The decolourisation of the dye involved adsorption of the dye compound by fungal pellets at the initial stage, followed by the decolourisation through microbial metabolism. Heat-killed pellets were also tested for their ability to decolourise Astrazon Red dye. These pellets adsorbed the dye and 55% decolourisation was obtained in 24 h. But at the second cycle there was only 24% decolourisation. Our observation showed that Astrazon Red dye decolourisation by heat-killed pellets was mainly due to biosorption. The longevity of the decolourisation activity of F. trogii pellets was also investigated in repeated batch mode. Variations in the amount of pellet increased % decolourisation and stability of pellets.


World Journal of Microbiology & Biotechnology | 1999

Plant growth hormone production from olive oil mill and alcohol factory wastewaters by white rot fungi

F. Yürekli; Ozfer Yesilada; M. Yürekli; S.F. Topcuoglu

In this study, olive oil mill and alcohol factory wastewaters have been tested as growth media for the production of plant growth hormones. Funalia trogii ATCC 200800 and Trametes versicolor ATCC 200801 have been tested. Gibberellic acid (GA3), abscisic acid (ABA), indole acetic acid (IAA), and cytokinin were determined in the culture media of these fungi. Both organisms produced enhanced levels of all three hormones in the presence of either of the wastewaters.


Acta Biologica Hungarica | 2008

Antioxidative and metabolic responses to extended cold exposure in rats

Sengul Yuksel; Dilek Asma; Ozfer Yesilada

In this work, we investigated whether extended cold exposure increases oxidative damage and susceptibility to oxidants of rat liver, heart, kidney and lung which are metabolically active tissues. Moreover in this study the effect of cold stress on some of the lipid metabolic mediators were studied in rat experimental model. Male albino Sprague-Dawley rats were randomly divided into two groups: The control group (n=12) and the cold-stress group (n=12). Tissue superoxide dismutase (SOD), catalase (CAT), glutathion S-transferase (GST) and glutathion reductase (GR) activities and glutathion (GSH) were measured using standard protocols. The biochemical analyses for total lipid, cholesterol, trigliceride, HDL, VLDL and LDL were done on autoanalyzer. In cold-stress groups SOD activity was decreased in the lung whereas it increased in the heart and kidney. CAT activity was significantly decreased (except liver) in all the tissues in treated rats. GST activity of cold-induced rats increased in liver and heart while decreased in the lung. GR activity was significantly decreased (except in liver) in all the tissues in cold-stressed rats. GSH level was significantly increased in the heart but decreased in the lung of animals exposed to cold when compared to controls. It was found that among the groups trigliceride, total lipid, HDL and VLDL parameters varied significantly but cholesterol and LDL had no significant variance. In this study, we found that exposure of extended (48 h) cold (8 degrees C) caused changes both in the antioxidant defense system (as tissue and enzyme specific) and serum lipoprotein profiles in rats.


Archive | 2016

Innovation of Strategies and Challenges for Fungal Nanobiotechnology

Necdet Sağlam; Ozfer Yesilada; Ahmet Çabuk; Mesut Sam; Semran Saglam; Sedef Ilk; Ezgi Emul; Pınar Aytar Çelik; Ekrem Gurel

Nanotechnology involves the study and use of materials under the 100 nm scale, exploiting the different physiochemical properties exhibited by these materials at the nanoscale level. Microorganisms are the best model and role of action for the nano/biotechnological applications. This technology has become increasingly important for the biotechnology and the related sectors. Promising applications have been already employed in the areas of drug delivery systems using bioactive nanoencapsulation, biosensors to detect and quantify pathogens, chemical and organic compounds, alteration of food compositions, and high-performance sensors and film to preserve fruits and vegetables. Moreover, the taste of food and food safety can be improved by new nano-materials from the microbiological sources. The huge benefits from this technology have led to increases in the market investments in nanoscience and nanoproducts in several areas.


Archives of Environmental Protection | 2012

Removal of indigo carmine from an aqueous solution by fungus Pleurotus ostreatus

Sibel Kahraman; Filiz Kuru; Demet Dogan; Ozfer Yesilada

Abstract The role of fungi in the treatment of wastewater has been extensively researched. Many genera of fungi have been employed for the dye decolourization either in living or dead form. In this study, the removal of an acidic dye, Indigo Carmine (IC), from an aqueous solution by biosorption on dead fungus, Pleurotusostreatus, was investigated. The effects of contact time, initial dye concentration, amount of dead biomass, agitation rate and initial pH on dye removal have been determined. Experimental results show that an increase in the amount of dead biomass positively affected the dye removal. The highest removal was obtained at 150-200 rpm. Slightly lower removing activities were found at lower agitation rates. The dye adsorption effi ciency was not affected by pH except minor variation in the pH of 2-8. Color removal was observed to occur rapidly within 60 minutes. The removal of dye by dead biomass of P. ostreatus was clearly dependent on the initial dye concentration of the solution. Dye removal was reduced from 93% to 64% as concentration was increased from 50 to 500 mg/L Indigo Carmine. This study showed that it was possible to remove textile dyes by dead biomass of P. ostreatus.


Archive | 2018

Bioremediation and Decolorization of Textile Dyes by White Rot Fungi and Laccase Enzymes

Ozfer Yesilada; Emre Birhanli; Hikmet Geckil

Textile and dyeing industries use various synthetic dyes. Effluents, containing 5–10% of dyestuffs, are usually discharged into natural water bodies. Conventional biological systems are not efficient for bioremediation and decolorization of dyes.


Archive | 2018

Bioremediation Applications with Fungi

Necdet Sağlam; Ozfer Yesilada; Semran Saglam; Elif Apohan; Mesut Sam; Sedef Ilk; Ezgi Emul; Ekrem Gurel

Industrial wastewaters such as olive oil mill wastewater (OOMW) and alcohol factory wastewater (vinasse) with high polluting characteristics affect the ecosystem seriously. The environmental impact of these wastewaters is rather severe due to their organic matter content and dark color. Therefore, it is illegal to dispose these wastewaters directly into the environment. In addition of wastewater treatments, decolorization of Kraft mills is one of the serious problems in pulp and paper industries because of their high color contents. The discharges of Kraft mills present a threat for environment and especially surface waters. These colored effluents contain serious amounts of chlorinated and oxidized lignin compounds. Remediation of this kind of wastewaters by conventional treatment methods has difficult and challenging processes. As a solution, the fungi have been chosen for bioremediation of wastewaters as efficient biological systems as they are able to remove the color and threatful organic content. Mycoremediation is an effective and ecofriendly method for the bioremediation of this type of wastewaters. This method has several advantages over chemical or physical remediation. Besides, fungal enzymes have a great potential for detoxifying and screening most of the environmental pollutants. In the last decade, fungal enzymes have a new application area on sensor technology. Biosensors are able to utilize fungal enzymes including an electrode that may be used for the detection of pollutants such as phenolic compounds. The objective of this chapter is to summarize recent developments in mycoremediation of wastewaters, especially OOMW and vinasse. Here, the role of biotechnologically important fungi such as yeast, molds, and white rot fungi in the mycoremediation of wastewaters is reviewed. The various mycoremediation methods for effective bioremediation and recent developments for fungal enzymes are also discussed.


Enzyme and Microbial Technology | 2006

Increased production of laccase by pellets of Funalia trogii ATCC 200800 and Trametes versicolor ATCC 200801 in repeated-batch mode

Emre Birhanli; Ozfer Yesilada


Engineering in Life Sciences | 2005

Biosorption of copper(II) by live and dried biomass of the white rot fungi Phanerochaete chrysosporium and Funalia trogii

S. Kahraman; Dilek Asma; S. Erdemoglu; Ozfer Yesilada

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Ahmet Çabuk

Eskişehir Osmangazi University

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Ekrem Gurel

Abant Izzet Baysal University

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