Dilek Asma

Decolorization of textile dyes by fungal pellets

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.

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

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.

Antioxidative and metabolic responses to extended cold exposure in rats

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.

Synthesis of NiO Nanostructures Using Cladosporium Cladosporioides Fungi for Energy Storage Applications

In this work, we produced nickel oxide nanostructures that show high electrochemical capacitive behaviour, using fungus – one of the most common life forms in nature. Cladosporium cladosporioides fungi are particularly attractive biotemplates due to their tubular structures. The nanostructured porous microtubes were prepared by chemical precipitation onto fungi. The morphological properties of the biosynthesized NiO microtubes were studied by transmission electron microscope (TEM). The Brunauer–Emmett–Teller (BET) surface area was found to be 119.72 m2 g−1 with an average pore size distribution of 7.5 nm. A maximum capacitance value of 334 F g−1 was observed at 0.8 A g−1, and a capacitance retention of approximately 95% was obtained after 1000 cycles.

Effects of endosulfan, thiamethoxam, and indoxacarb in combination with atrazine on multi-biomarkers in Gammarus kischineffensis

Studies addressing the toxicity of pesticides towards non-target organisms focus on the median lethal concentration and biochemical response of individual pesticides. However, when determining environmental risks, it is important to test the combined effects of pesticides, such as insecticides and herbicides, which are frequently used together in agricultural areas. Here we aimed to investigate the toxic effects of the combined use of the herbicide atrazine and the insecticides, endosulfan, indoxacarb, and thiamethoxam on Gammarus kischineffensis. To do this, we tested the activities of oxidative stress, detoxification, and neurotoxicity biomarkers. Compared to atrazine alone, we detected higher glutathione-S-transferase, catalase and superoxide dismutase activities (oxidative stress biomarkers) when atrazine was combined with either endosulfan or indoxacarb. However, higher IBR values were determined in organisms where pesticide mixtures were used according to individual use. Based on these results, mixtures of atrazine and other pesticides may cause synergistic effects and may be evidence of increased toxicity and oxidative stress.