Yazar "Ertan, Figen" seçeneğine göre listele
Listeleniyor 1 - 13 / 13
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Aspergillus niger' den ürikaz enziminin üretilmesi ve aktiviteye etkili bazı faktörlerin belirlenmesi(2000) Aksöz, Erol; Ertan, Figen[Abstract Nıt Available]Öğe Bugday ve pirinç alfa amilazi üzerine endosülfanin etkisinin radyal difüzyon teknigi ile gösterilmesi(1997) Aktaç, Tülin; Ertan, Figen; Ekıncı, Filiz[Abstract Nıt Available]Öğe Comparison off some properties of free and immobilized ?-amylase by Aspergillus sclerotiorum in calcium alginate gel beads(Taylor & Francis Inc, 2008) Yagar, Hulya; Ertan, Figen; Balkan, BilalSome properties of immobilized a-amylase by Aspergillus sclerotiorum within calcium alginate gel beads were investigated and compared with soluble enzyme. Optimum pH and temperature were found to be 5.0 and 40 degrees C, respectively, for both soluble and immobilized enzymes. The immobilized enzyme had a better Km value, but k(cat)/K-m values were the same for both enzymes. Entrapment within calcium alginate gel beads improved, remarkably, the thermal and storage stability of a-amylase. The half life values of immobilized enzyme and soluble enzyme at 60 degrees C were 164.2, and 26.2 min, respectively. The midpoint of thermal inactivation (T-m) shifted from 56 degrees C (for soluble enzyme) to 65.4 degrees C for immobilized enzyme. The percentages of soluble starch hydrolysis for soluble and immobilized alpha-amylase were determined to be 97.5 and 92.2% for 60 min, respectively.Öğe Determination of Some Properties of Free and Immobilized Urease from Aspergillus fumigatus and Its Application in Urea Assay(Chem Soc Pakistan, 2016) Tetiker, Aylin Turksever; Ertan, FigenUrease enzyme was extracted from Apergillus fumigatus and immobilized in calcium alginate beads. The immobilization efficiency was calculated as 82.5 %. Optimum pH and temperature for free and immobilized enzymes were found to be 7.0 and 40 degrees C, respectively. The immobilized urease had a better Km value but, catalytic efficiencies (kcat/Km) were very similar. Immobilized enzyme maintained 44% of its initial activity after 5 repeated use of enzyme. It was found that storage stability of immobilized enzyme was better than that of the free enzyme. Immobilized urease enzyme was used for the determination of urea amounts in animal feed.Öğe THE EFFECTS OF METHYLEUGENOL ON THE LIVER, KIDNEY AND SMALL INTESTINE AND ON THE ANTIOXIDANT ENZYMES IN RATS(Parlar Scientific Publications (P S P), 2009) Kaboglu, Aysegul; Ertan, Figen; Kizilay, GulnurMethyleugenol is a natural, widely used constituent of foods. cosmetics, soaps and shampoos. The purpose of this study was to evaluate the effects of methyleugenol on the liver, kidney and small intestine. Methyleugenol was given by gavage to rats for ten days at doses of 10 mg/kg and 30 mg/kg. In liver, widening of the sinusoidal area, necrotic and hypertrophic hepatocytes, cytoplasmic vacuolization in hepatocytes, degeneration of endothelium, mononuclear cell infiltration, and picnotic nuclei were observed. In kidney, loosing of glomerulus, mononuclear cell infiltration, focal bleeding around tubules, degenerative tubules, epithelial membrane degeneration, hypertrophic epithelial cells, and accumulation of material in proximal tubules were observed. In small intestine, increased mitotic figures in the base of villi, edema in connective tissue, connective-epithelial tissue separation, diminished connective tissue in lamina propria, a foam-like appearance, and leukocyte infiltration were observed. There were no significant changes in superoxide dismutase (SOD) and catalase (CAT) activity, but glutathione peroxidase (GPX) activity was significantly increased in the kidney and small intestine at 30 mg/kg (p<0.05). The amount of total protein was significantly increased in liver (p<0.05). but not changed in the kidney and small intestine. We concluded that the toxic effects of methyleugenol must be evaluated in greater detail.Öğe Farklı Ham Nişasta İçeren Tarama Besiyerlerinde Farklı Fungus Türlerinin Amilolitik Aktiviteleri(Trakya Üniversitesi, 2010) Balkan, Bilal; Aydoğdu, Halide; Balkan, Seda; Ertan, FigenThirty-nine fungal species were screened for the production of extracellular amylase hydrolyzing raw starch using a plate culture method. Czapek-Dox Agar containing different raw starch (corn, wheat, potato and rice) was used as culture medium for screening. Among these, thirteen, twelve, seven and five fungi showed higher amylolytic activity on solid medium containing raw wheat starch, raw rice starch, raw potato starch and raw corn starch, respectively. Two fungi did not show any amylolytic activityÖğe Immobilization of B. amyloliquefaciens ?-amylase and comparison of some of its enzymatic properties with the free form(Ars Docendi, 2011) Demirkan, Elif; Dincbas, Serhan; Sevinc, Nihan; Ertan, FigenThe enzyme alpha-Amylase from Bacillus amyloliquefaciens was entrapped by drop-wise addition of an aqueous mixture of sodium alginate in the solution of a Ca2+ salt. Effects of immobilization conditions were investigated. Optimum alginate and CaCl2 concentrations were found to be 2% and 5% (w/v), respectively. The immobilization yield was 89%. Amylase activity increased with increasing enzyme loading on the beads. The best size and amount of beads for achieving enzyme activity were found to be 3 mm and 0.4 g, respectively. When coated with silicate, amylase-entrapped beads retained the highest catalytic activity. The highest operational stability was six reuses with 51% residual activity. Some properties of immobilized enzyme were determined, and compared with those of free enzyme. Product profile of the various raw starches has been determined by thin layer chromatography.Öğe Optimization of ?-amylase immobilization in calcium alginate beads(Taylor & Francis Inc, 2007) Ertan, Figen; Yagar, Hulya; Balkan, Bilalalpha-Amylase enzyme was produced by Aspergillus sclerotiorum under SSF conditions, and immobilized in calcium alginate beads. Effects of immobilization conditions, such as alginate concentration, CaCl2 concentration, amount of loading enzyme, bead size, and amount of beads, on enzymatic activity were investigated. Optimum alginate and CaCl2 concentration were found to be 3% (w/v). Using a loading enzyme concentration of 140 U mL(-1), and bead (diameter 3 mm) amount of 0.5 g, maximum enzyme activity was observed. Beads prepared at optimum immobilization conditions were suitable for up to 7 repeated uses, losing only 35% of their initial activity. Among the various starches tested, the highest enzyme activity (96.2%) was determined in soluble potato starch hydrolysis for 120 min at 40 degrees C.Öğe Production and Determination of Some Biochemical Properties of Protease Enzyme by Trichothecium roseum Under Solid State Fermentation(Ars Docendi, 2012) Ozkan, Ebru; Ertan, FigenSome fungal species were searched in terms of protease production by using casein degrading protease screening methods and it was found that Trichothecium roseum Penicillium piceum, Penicillium chrysogenum and Aspergillus wentii had the highest protease activity. Solid state fermentation was carried out by using wheat bran as substrate and it was determined that T. roseum had the highest protease activity. A number of culture conditions for protease production by T. roseum under SSF were investigated. Maximal protease production was obtained with initial moisture content of 85 % (w/v), an inoculum level of 2 mL (1x10(6) spore/mL) when incubated at 30 degrees C for 7 days. Maximum activity of protease with casein as a substrate was observed after 10 minutes at 40 degrees C temperature and at pH 6.5. The K-m and V-max values of protease for casein as substrate were calculated to be 6.06 (mg/mL) and 121.95 (U/mL), respectively.Öğe Production of ?-amylase from Penicillium chrysogenum under solid-state fermentation by using some agricultural by-products(Faculty Food Technology Biotechnology, 2007) Balkan, Bilal; Ertan, FigenSolid-state fermentation (SSF) was carried out using corncob leaf (CL), rye straw (RS), wheat straw (WS) and wheat bran (WB) as substrates for a-amylase production by a fungal culture of Penicillium chrysogenum. The effects of moisture level, particle size and inoculum concentration on enzyme synthesis from R chrysogenum were investigated. Optimal moisture levels of substrates were 75, 65, 65 and 55% for CL, WS, WB and RS substrates, respectively. Optimal particle size and inoculum concentration for the production of alpha-amylase were: >1 mm, 20%; >1 mm, 20%; 1 mm, 20% and >1 mm, 30% for CL, WS, WB and RS, respectively WB showed the highest enzyme production with 160 U/mL under optimum conditions. The other enzyme activities were 28, 49 and 45 U/mL using CL, RS and WS, respectively.Öğe THE PRODUCTION OF A NEW FUNGAL -AMYLASE DEGRADED THE RAW STARCH BY MEANS OF SOLID-STATE FERMENTATION(Taylor & Francis Inc, 2010) Balkan, Bilal; Ertan, FigenIn this study, it was intended to produce a new fungal amylase by solid-state fermentation and purification and also to determine some of its biochemical properties. It was found that Penicillium brevicompactum had the best enzyme activity according to screening methods with amylase degrading raw starch, and P. brevicompactum was selected as the amylase source. Wheat bran, rice husks, and sunflower oil meal were tested to determine the best solid substrate. Wheat bran was determined as the best of these. The fermentation conditions were optimized for the production of amylase. The optimum fermentation conditions were found to be an initial moisture level for the solid substrate of 55%, moistening agent of 0.1M sodium phosphate buffer (pH 5.0), incubation period of 7d, inoculum concentration of 2.5mL, and incubation temperature at 30 degrees C. Penicillium brevicompactum -amylase was purified 45.98 times by the starch affinity method. The Km and Vmax values of -amylase for soluble starch were 5.71mg/mL and 666.6U/mL, respectively. This amylase showed maximum activity at between 30 and 50 degrees C and at pH 5.0. Initial enzyme activity was kept at 100% after incubation at 30 degrees C for 45min. Enzyme was stable in the pH range of 4.0-5.0. This enzyme was activated by Mn2+, Cu2+, and Na+ ions, and was inhibited by Mg2+, K+, Fe3+, and ethylenediamine tetraacetic acid (EDTA). The molecular mass of P. brevicompactum -amylase was found to be 32.5kD by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis.Öğe Solid state fermentation for the production of ?-amylase from Penicillium chrysogenum using mixed agricultural by-products as substrate(Springer, 2006) Ertan, Figen; Balkan, Bilal; Balkan, Seda; Aktac, TulinProduction of a-amylase from local isolate, Penicillium chrysogenum, under solid-state fermentation (SSF) was carried out in this study. Different agricultural by-products, such as wheat bran (WB), sunflower oil meal (SOM), and sugar beet oil cake (SBOC), were used as individual substrate for the enzyme production. WB showed the highest enzyme activity (750 U/gds). Combination of WB, SOM, and SBOC (1:3:1 w/w/w) resulted in a higher enzyme yield (845 U/gds) in comparison with the use of the individual substrate. This combination was used as mixed solid substrate for the production of a-amylase from P. chrysogenum by SSF. Fermentation conditions were optimized. Maximum enzyme yield (891 U/gds) was obtained when SSF was carried out using WB + SOM + SBOC (1:3:1 w/w/w), having initial moisture of 75 %, inoculum level of 20 %, incubation period of 7 days at 30 degrees C. Galactose (1 % w/w), urea and peptone (1 % w/w), as additives, caused increase in the enzyme activity.Öğe Ultrastructural changes in rat liver by methyleugenol and evaluation of some biochemical parameters(Tubitak Scientific & Technological Research Council Turkey, 2010) Cerkezkayabekir, Aysegul; Kizilay, Gulnur; Ertan, FigenThe present study investigated the effect of methyleugenol, a food flavoring and fragrance agent, on the livers of laboratory rats. Doses of 10 and 30 mg/kg/day of methyleugenol (in 0.5% methylcellulose) were administered intragastrically (IG) to 2 dose groups for 10 days alongside a control group (n = 10 for each group). Gains in body weight were not statistically significant for either dose. Lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) activities decreased (P < 0.05) for both dose groups, but AST (aspartate aminotransferase) activity decreased significantly (P < 0.05) only in the 30 mg/kg/day methyleugenol dose group. Alanine aminotransferase (ALT) activity did not change significantly in either group. The total amount of glucose remained unchanged, but glycogen in the liver decreased significantly (P < 0.05) in the 30 mg/kg/day methyleugenol dose group. There was also an increase of swelling in the smooth endoplasmic reticulum sacs (sER), electron dense accumulations in the sER, cytoplasmic vacuolization, a slight increase of mitochondria and lysosomes, and invaginations in the nucleus membranes of hepatocytes. Extensions in bile canaliculi and increasing microvilli of bile canaliculi in the liver were also observed. These findings indicate the ultrastructural toxic effect of methyleugenol on rat livers in 10 and 30 mg/kg/day doses. Therefore, we may speculate that the toxic effect of methyleugenol needs to be examined in detail.
