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Öğe Anticancer and Antimicrobial Activities of New Cobalt and Zinc Complex-Derived Benzimidazole Containing Nitro or Methyl Groups(Amer Chemical Soc, 2026) Yilmaz, Ozgur; Apohan, Elif; Yesilada, Ozfer; Yilmaz, Ulku; Kucukbay, HasanThe cytotoxic effects of six newly synthesized 5(6)-methyl or 5(6)-nitrobenzimidazole-derived compounds that contain cobalt and zinc on nonsmall cell lung carcinoma (A549) and healthy lung epithelial (BEAS-2B) cell lines were evaluated by MTT, caspase-3, and Western Blotting methods. Cisplatin was also used as a reference compound. Compound 4 and compound 5 exhibited high cytotoxic activity against A549. While the IC50 value of cisplatin was 14.31 mu M, IC50 values of compound 4 and compound 5 were 10.30 and 7.01 mu M on A549 cells at 72 h, respectively. On the other hand, for BEAS-2B cells, the IC50 values of cisplatin, compound 4, and compound 5 were 5.91, 90.13, and 51,68 mu M, respectively. The results showed that although compounds 4 and 5 have high cytotoxicity on A549 cells, similar to cisplatin, they are less cytotoxic to BEAS-2B cells than cisplatin. The antibacterial and antifungal properties of the synthesized compounds were also investigated using minimum inhibitory concentration method. Their antimicrobial activities were tested against the Gram-negative bacteria Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853, Gram-positive Staphylococcus aureus ATCC 29213, and yeast species Candida albicans ATCC 90028 and Candida tropicalis. The compounds showed notable antimicrobial activity against these pathogenic bacteria and yeasts.Öğe Antioxidative and metabolic responses to extended cold exposure in rats(Akademiai Kiado Zrt, 2008) Yuksel, Sengul; Asma, Dilek; Yesilada, OzferIn 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 C) caused changes both in the antioxidant defense system (as tissue and enzyme specific) and serum lipoprotein profiles in rats.Öğe Bacterial Cellulose Production in Dried Apricot Extract Medium: Experimental/Theoretical Characterization and Application in Yeast Immobilization for Dye Removal(Amer Chemical Soc, 2025) Boran, Filiz; Koytepe, Suleyman; Aslan, Gizem; Birhanli, Emre; Yesilada, Ozfer; Alagoz, Mehmet AbdullahBacterial cellulose (BC) was produced in dried apricot extract medium (DAEM) by Gluconacetobacter xylinus B759. The BC yield obtained from DAEM containing 0.5 g of glucose after 10 days of incubation at 30 degrees C was determined as 9.67 g/L. BC was used as an immobilization matrix for Saccharomyces cerevisiae. First, structural characterizations of BC and BC-yeast were carried out. Also, their surface and morphological properties were examined by SEM and atomic force microscopy. Yeast attachment and growth kinetics were also evaluated experimentally and theoretically. This yeast-immobilized BC (BC-yeast) membrane was used for removal of textile dye, Reactive Blue 171 (RB 171). The results showed that yeast was successfully immobilized on BC and could be effectively used for dye removal. When 12 lyophilized BC-yeast samples were used, 52% and 21% dye removal values were obtained under static and shaking (150 rpm) conditions, respectively. These values were 49% and 50% for wet BC-yeast samples after 24 h, respectively. Additionally, density functional theory calculations were performed to elucidate the interactions responsible for the adsorption of RB 171 dye onto the BC structure, and it was shown that the RB 171 structure is energetically very strong and favorably bound to the BC surface. It was found that BC-yeast was highly effective for RB 171 removal. Therefore, the BC produced in DAEM could be used as an immobilization matrix and as a low-cost, effective, and alternative adsorbent for the removal of dyes from dye-containing wastewaters.Öğe Bioremediation and Decolorization of Textile Dyes by White Rot Fungi and Laccase Enzymes(Springer International Publishing Ag, 2018) Yesilada, Ozfer; Birhanli, Emre; Geckil, Hikmet[Abstract Not Available]Öğe Bioremediation Applications with Fungi(Springer International Publishing Ag, 2018) Saglam, Necdet; Yesilada, Ozfer; Saglam, Semran; Apohan, Elif; Sam, Mesut; Ilk, Sedef; Emul, Ezgi[Abstract Not Available]Öğe A comparative study on decolorization of reactive azo and indigoid dyes by free/immobilized pellets of Trametes versicolor and Funalia trogii(Triveni Enterprises, 2015) Yildirim, Seval Cing; Yesilada, OzferThe objective of the present study was to investigate decolorization of Acid Blue 74 and Reactive Blue 198 dyes by free and immobilized white rot fungal pellets in order to confirm the possibility of practical application via repeated-batch cultivation. Decolorization studies were conducted using free pellets (FP), fungal cells immobilized on activated carbon (IFCAC) and pinewood (IFCP), and also fungal cells entrapped in alginate beads (FCEAB). No additional nitrogen and carbon source was used and high decolorization rates were achieved in only dye-contained media without pH adjustment. Acid Blue 74 was decolorized 96 and 94% within 2 hr by Trametes versicolor and Funalia trogii free pellets, respectively. These values were 87 and 84% for Reactive Blue 198, in this respect. Immobilization of fungal cells on pinewood increased the usability of pellets and the average decolorization efficiency of both dyes. The micro environment changed in the presence of pinewood and increased the stability of immobilized pellets. Decolorization was performed rapidly and efficiently. Laccase activity enhanced with availability of pinewood, and high laccase production with F trogii was obtained. After separation by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), the molecular weight of Trametes versicolor and F trogii laccase bands was determined 64 and 61 kDa approximately. Green bands were obtained by the activity staining process with laccase substrate (ABTS) after gel renaturation step.Öğe Comparison of Dye Decolorization Potential of Gluconacetobacter xylinus and Newly Isolated Trametes trogii(ABADER (Adiyaman Bilimsel Arastirmalar Dernegi), 2025) Yalcin, Muge; Boran, Filiz; Yesilada, OzferIn this study, the dye removal ability of Gluconacetobacter xylinus NRRL B759 during bacterial cellulose production and dye decolorization efficiency of the newly isolated white rot fungus Trametes trogii were investigated. The most efficient results for Reactive Blue 171 dye were obtained on the 6th day under both static and agitated conditions at 30°C. The best results for Remazol Brilliant Blue R dye were determined at 30°C on the 10th and 8th days for static and agitated conditions, respectively. Most importantly, it was observed that biosorption was the main mechanism for dye removal activity of this bacterium. The decolorization ability of fungus was investigated under batch and repeated-batch processes. The most effective decolorization values were 48% on the 8th day for RB171 dye and 83% on the 6th day for RBBR dye under batch process. Decolorization activity of the pellets was tested under repeated-batch experiments in both distilled water and Sabouraud Dextrose Broth (SDB) media. In distilled water media, lower decolorization values were obtained for both dyes compared to SDB media. In SDB medium for RB171, the decolorization values are 70% in the 1st cycle and 19% in the 5th cycle. The RBBR dye decolorization values was 57% in the 1st cycle, while this value was reached 74% in the 5th cycle. The decolorization mechanism of the pellets was mainly a result of microbial metabolism. © 2025 ABADER (Adiyaman Bilimsel Arastirmalar Dernegi). All rights reserved.Öğe Cytotoxic and antimicrobial potential of benzimidazole derivatives(Wiley-V C H Verlag Gmbh, 2021) Kucukbay, Hasan; Uckun, Mustafa; Apohan, Elif; Yesilada, OzferNew benzimidazole derivatives were synthesized and their structures were characterized by spectroscopic and microanalysis techniques. The cytotoxic properties of ten benzimidazole derivatives, five of which were synthesized in our previous studies, were determined against the lung cancer cell line, A549, and the healthy lung epithelial cell line, BEAS-2B. Among the ten compounds tested, based on the 72-h incubation results, compound 12 was the most cytotoxic against the A549 cell line, whereas against the BEAS-2B cell line, it was as cytotoxic as cisplatin. The IC50 values of compound 12 were 3.98 and 2.94 mu g/ml for A549 and BEAS-2B cells, respectively. The cisplatin values were 6.75 and 2.75 mu g/ml for A549 and BEAS-2B cells, respectively. Compounds 10, 8, 7, and 13 showed toxic effects against A549 cells, but were less toxic against BEAS-2B cells than cisplatin. The antimicrobial activity of these compounds against pathogenic bacteria and yeasts was also evaluated based on their minimum inhibitory concentration (MIC) values. The compounds, except 12 and 13, generally showed higher antimicrobial activity against yeasts, compared with bacteria. Compound 12 showed better activity against Pseudomonas aeruginosa and Staphylococcus aureus than against Escherichia coli. Compounds 7, 8, and 11 were the most effective ones against the microorganisms, and yeasts were highly sensitive to these compounds with MIC values of 25-100 mu g/ml.Öğe Design of laccase-metal-organic framework hybrid constructs for biocatalytic removal of textile dyes(Pergamon-Elsevier Science Ltd, 2022) Birhanli, Emre; Noma, Samir Abbas Ali; Boran, Filiz; Ulu, Ahmet; Yesilada, Ozfer; Ates, BurhanThis study aims to present a simple and effective carrier matrix to immobilize laccase as opposed to complex and tedious immobilization processes and also to use it in the removal of textile dyes. For this purpose, Cobalt (Co) and Copper (Cu) based metal-organic frameworks (MOFs) were prepared and laccase was immobilized on two different MOFs via encapsulation. The characterization outcomes showed that laccase was well immobilized into MOF supports. Optimum pH and temperature were found for Lac/Co-MOF (pH 4.5 at 50 degrees C) and Lac/Cu-MOF (pH 5.0 at 50 degrees C). The Km (0.03 mM) and Vmax (97.4 mu mol/min) values of Lac/Cu-MOF were lower than those of Lac/Co-MOF (Km = 0.13 mM, Vmax = 230.7 mu mol/min). The immobilized laccases showed good reusability as well as improved resistance to temperature denaturation and high storage stability. For instance, the Lac/Co-MOF and Lac/Cu-MOF retained more than 58% activity after 4 weeks of storage at room temperature. Meanwhile, Lac/Co-MOF and Lac/Cu-MOF maintained 56.5% and 55.8% of their initial activity, respectively, after 12 reuse cycles. Moreover, thermal deactivation kinetic studies of immobilized laccases displayed lower k value, higher t1/2, and enhancement of thermodynamic parameters, which means better thermostability. Finally, the decolorization activities for the Lac/Co-MOF were 78% and 61% at the 5th cycle for Reactive Blue 171 andÖğe Dye removal by dead biomass of newly isolated Pleurotus ostreatus strain(Natl Inst Science Communication-Niscair, 2018) Dogan, Demet; Boran, Filiz; Kahraman, Sibel; Akmil-Basar, Canan; Yesilada, OzferDead biomass prepared from newly isolated Pleurotus ostreatus strain was tested for their efficiency in removal of indigo carmine. The effects of operational parameters such as contact time, initial dye concentration, amount of biomass, initial pH and agitation rate on removal were examined. The dye removal increased rapidly during the first 60 minutes (87%) and remained nearly constant between 60 - 120 minutes of adsorption (87 - 90%). The removal of dye by dead biomass of newly isolated P. ostreatus was clearly dependent on the initial dye concentration of the solution and dye removal was reduced from 83% to 53% as concentration was increased from 100 to 500 mg/L indigo carmine. Results were analyzed by the Langmiur, Freundlich, Dubinin-Redushkevich (D-R), Temkin, Frumkin, Harkins-Jura, Halsey, Henderson isotherm using linearised correlation coefficient. The kinetics of adsorption of IC have been discussed using six kinetic models, i.e., the pseudo first order model, the pseudo second order model, the Elovich equation, the intraparticle diffusion model, the Bangham equation, the modified Freundlich equation. In order to determine the best fit isotherm and kinetic models, three error analysis methods of residual mean square error (RMSE), chi-square (X-2) statistic and the average percentage error (APE%) were used to evaluate the data.Öğe The effect of various inducers and their combinations with copper on laccase production of Trametes versicolor pellets in a repeated-batch process(Tubıtak scıentıfıc & technıcal research councıl turkey, ataturk bulvarı no 221, kavaklıdere, ankara, 00000, turke, 2017) Birhanli, Emre; Yesilada, OzferThe aim of this study was to increase laccase production in Trametes versicolor ATCC 200801 pellets by using various inducers and their combinations under repeated-batch conditions. Because copper is an effective inducer for laccase production, the effect of Cu on laccase production in this strain was tested first. The optimal Cu concentration for the highest laccase production was 0.5 mM. Following this preliminary study, the effect of other inducers [2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), syringaldazine, guaiacol, and 2,5-xylidine] on laccase production was determined. Copper was determined to be the most efficient inducer among the inducers used. Therefore, the synergistic effect of each inducer with Cu on laccase production in this strain was investigated. While the maximum laccase activity was 0.60 U/mL in stock basal medium (SBM) alone, the highest enzyme activities detected were 4.76 and 2.87 U/mL in SBM + 0.05 mM ABTS and SBM + 1 mM 2,5-xylidine, respectively. Maximum laccase activities obtained from the combination of the inducers were 33.61 and 26.49 U/mL in SBM + 0.5 mM Cu + 0.5 mM 2,5-xylidine and SBM + 0.5 mM Cu + 0.05 mM ABTS, respectively. These were the most efficient combinations for laccase production.Öğe ENHANCED PRODUCTION OF LACCASE BY FUNGI UNDER SOLID SUBSTRATE FERMENTATION CONDITION(North Carolina State Univ Dept Wood & Paper Sci, 2011) Boran, Filiz; Yesilada, OzferFunalia trogii and Trametes versicolor were grown on agro byproduct wheat bran moistened with various natural moistening agents, and their effects on laccase production under solid substrate condition were investigated. Laccase was the main enzyme detected under this condition. High levels of laccase activity were obtained with solid substrate cultures moistened with olive oil mill wastewater (OOMW) or alcohol factory wastewater (vinasse). Among the cultures without inducer, T. versicolor culture was detected as a more effective laccase producer than F. trogii culture. Copper and xylidine were used as laccase inducers, and copper induced laccase production more than xylidine. The maximum laccase activity was detected as 14.18 U/mL with F. trogii grown on wheat bran moistened with 5 mM CuSO4 center dot 5H(2)O added 25% vinasse. Azo dye decolorization activity of the supernatants from solid substrate cultures was also tested. While the use of 0.063 U/mL F. trogii laccase in reaction solution gave 66% decolorization in a minute, it was 14% for T. versicolor. This method can be a possible alternative for valorization of lignocellulosic materials and industrial wastewaters during solid substrate fermentation and for obtaining enzyme source with very high decolorization activity.Öğe Enhanced production of laccase in repeated-batch cultures of Funalia trogii and Trametes versicolor(Elsevier Science Bv, 2010) Birhanli, Emre; Yesilada, OzferThe biotechnologically important enzyme laccase (benzenediol: oxygen oxidoreductase: EC 1.10.3.2) is secreted by white rot fungi. However, these organisms produce insufficient amount of laccase for use in various biotechnological areas. The main aim of this study is to enhance the laccase production in the repeated-batch cultures of Funalia trogii ATCC 200800 and Trametes versicolor ATCC 200801 isolated in Turkey. In this study, laccase production in the repeated-batch cultures of F. trogii and T. versicolor pre-grown pellets were investigated under various conditions. Retention time, temperature, agitation, pH and the amount of pellets were found to be important for laccase production during repeated-batch studies. The culture filtrate showed one protein band. Zymogram gel also showed only one band of activity. The enzyme remained fully active when frozen for 300 clays. The immobilized fungi were also able to produce high amounts of laccase during reuse. It is possible to obtain high laccase amounts with free and immobilized repeated-batch cultures under the most appropriate culture conditions determined. Considering the various biotechnological applications of laccase, an enhancement in laccase production through the selection of appropriate culture conditions could facilitate the development of more economical and environmentally friendly processes. (C) 2010 Elsevier B.V. All rights reserved.Öğe ENHANCEMENT OF LACCASE PRODUCTION OF PRE-GROWN FUNGAL PELLETS IN WASTEWATER OF OLIVE OIL MILLS(Parlar Scientific Publications (P S P), 2011) Apohan, Elif; Yesilada, OzferPrevious works reported laccase production ability of batch cultures of white rot fungi in olive oil mill wastewater media (OOMW). Therefore, here, laccase production ability of repeated-batch cultures of Funalia trogii and Trametes versicolor pre-grown pellets in olive oil mill wastewater media (OOMW) was investigated and conditions for laccase production were optimized. The results indicated that high amounts of laccase could be obtained by using the best production conditions such as agitation, initial pellet amounts, initial pH, OOMW concentration and temperature. All these conditions were found to be important for laccase production. After optimization, the effect of various supplementary sources and inducer (glucose, malt extract, cheese whey and copper) on laccase production ability of these fungi and longevity of this production ability were examined in repeated-batch process. Presence of glucose, malt extract, cheese whey and copper positively affected the laccase production ability and longevity of the production. The fungal pellets also partially bioremediated the OOMW during laccase production and F. trogii pellets removed 33 % COD from OOMW effluent whilst T. versicolor removed 28 % in the first use.Öğe Ephedra alata Growing Wild in Southern Tunisia: Phytochemical Profiling and Anti-Inflammatory, Antibacterial, Anti-xanthine Oxidase and Cytotoxic Potentials(Natl Information Documentation Cent, Acad Scientific Research & Technology, 2026) Bennour, Naima; Mighri, Hedi; Harboub, Nesrine; Eljani, Hajer; Chouikhi, Naima; Yesilada, Ozfer; Campra, PabloThis study investigated the ethnobotanical use, phytochemical composition, and biological activities of Ephedra alata from southern Tunisia. Ethnobotanical data were collected via an online questionnaire, and proximate, phytochemical, and mineral analyses were performed using standard methods. Extracts obtained with dichloromethane, ethyl acetate, butanol, ethanol, and water were assessed for total phenolic content (TPC) and total flavonoid content (TFC), as well as for anti-inflammatory (5-lipoxygenase inhibition), anti-xanthine oxidase, cytotoxic (HT-29 cell line), and antibacterial (MIC against Staphylococcus aureus and Escherichia coli) activities. Among 450 respondents, 64% were familiar with Ephedra and 27% reported its use mainly aerial parts via infusion for cancer, digestive issues, and hypertension. Nutritional analysis revealed high fiber (41.6%), protein (9.45%), and mineral content. Phytochemical screening identified 9 of 17 targeted compounds. Mineral analysis confirmed the presence of Na, K, Ca, Mg, Zn, and Fe. Ethanol extracts showed the highest anti-xanthine oxidase (IC50 = 143mg/L) and cytotoxic activity (GI50= 780mg/L), while overall anti-inflammatory and antibacterial effects were weak. These findings support the traditional use of E. alata and highlight its potential in health and nutrition applications.Öğe The evaluation of pre-grown mycelial pellets in decolorization of textile dyes during repeated batch process(Springer, 2010) Yesilada, Ozfer; Yildirim, Seval Cing; Birhanli, Emre; Apohan, Elif; Asma, Dilek; Kuru, FilizThis study was undertaken for the possibility of application of pre-grown pellets for biotechnological treatment of dyes and textile industry waste waters. Mycelial pellets of five different white rot fungi were tested for their dye decolorization activity. The pellets of Funalia trogii, Phanerochaete chrysosporium and Trametes versicolor were determined as the most effective ones. The decolorization ability of viable pellets was compared with the decolorization (adsorption) ability of dead pellets during repeated batch studies. Astrazon Black dye was decolorized effectively, about 90%, by viable pellets of all fungi during the first use. Viable F. trogii pellets were found as the most effective pellets. Upon pellet treatment not only a high decolorization but also reduced toxicity (antimicrobial activity) of the Astrazon Black dye was recorded. This type of decolorization activity with commercial or crude laccase was partially observed. Growing cells of F. trogii in batch system showed lower efficiency in color removal of mixed dyes compared to the pre-grown pellets in repeated batch system. The results in this study showed that mycelial pellets could effectively be used as an alternative to traditional physicochemical processes.Öğe Fabrication, characterization, and application of laccase-immobilized membranes for acetamiprid and diuron degradation(Elsevier, 2024) Ulu, Ahmet; Akkurt, Seyma; Birhanli, Emre; Uckun, Aysel Alkan; Uckun, Mirac; Yesilada, Ozfer; Ates, BurhanWater and wastewater pollution by acetamiprid and diuron is considered a serious environmental problem. In this study, chitosan (CHS), a naturally occurring bioadsorbent considered ecologically harmless to remove these micropollutants, was developed as a possible carrier to immobilize laccase (Lac) from Trametes trogii. Polyethylene glycol methyl ether (PEGME) was chosen for blending CHS, so a hybrid biocatalyst-based Lac/CHSPEGME membrane was prepared. The prepared CHS-PEGME and Lac/CHS-PEGME membranes were characterized by Fourier-transformed-infrared (FTIR) spectroscopy, scanning-electron-microscopy (SEM), and X-raydiffraction (XRD). Pesticide degradation tests with Lac/CHS-PEGME were performed at different contact times and initial concentrations. Acetamiprid degradation was most effective (84 %) at the 12th hour, at an initial concentration of 0.1 mg/L, while diuron degradation was most effective (65 %) at an initial concentration of 6 mg/L and a contact time of 16th hour. Under optimum conditions, the reusability of Lac/CHS-PEGME was found to be 8 cycles for acetamiprid and 5 cycles for diuron. From these results, it is understood that acetamiprid is degraded more quickly and effectively than diuron. Adsorption process data were well fitted to the Langmuir isotherm model and the pseudo-first-order kinetic model. These findings showed that using Lac/CHS-PEGME was a practical and environmentally friendly method for acetamiprid and diuron degradation.Öğe Facile construction of a robust and recyclable laccase/metal-organic framework-808 with boosted stability for biodegradation of Reactive Blue 171 and Reactive Blue 198 from aqueous media(Elsevier, 2024) Bakar, Busra; Bugday, Nesrin; Birhanli, Emre; Boran, Filiz; Ulu, Ahmet; Yasar, Sedat; Yesilada, OzferLaccase enzyme sees application demand in many industries such as textile, food processing, wood processing, pharmaceutical, and chemical. However, it becomes difficult to maintain the enzymatic activity of laccase under harsh reaction conditions and even after several biocatalytic cycles. Therefore, suitably prescribed supports are crucial to ensure that the catalytic activity and reusability of the immobilized laccase are maintained at high levels. The present study highlights the development and dye decolorization application of an enzyme carrier matrix employing a Zr-based metal-organic framework (MOF), MOF-808, with hierarchical porosity for the immobilization of laccase from Trametes trogii . The immobilization efficiency for Lac/MOF-808 was found to be 70.83 +/- 1.98 %. Lac/MOF-808 exhibited optimal catalytic temperature at 60 degrees C, while the optimal catalytic pH was 4.5. Due to recoverable properties from the carrier matrix the recycle test was satisfactory for the Lac/MOF808, being reused 7 times without losses greater than 50 % of residual activity. Stored at 25 degrees C, Lac/MOF-808 retained 30 % of its activity during 4-weeks period. A kinetic study was carried out for Lac/MOF-808 monitoring the oxidation reaction of ABTS. The K-m value was 0.070 mM and the V-max was 87.7 mu mol min(-1) g(-1). Kinetic investigations, on the other hand, demonstrated a decrease in K m following immobilization, signifying a higher affinity for substrate. The Lac/MOF-808 maintained its decolorization efficiency even after eight reaction cycles, exhibiting a remarkable activity of 56.7 % and 77.2 % against Reactive Blue 171 and Reactive Blue 198, respectively. Hence, the described Lac/MOF-808 might be an ideal candidate for efficient dye decolorization applications.Öğe Immobilization of laccase isolated from Trametes trogii on chitosan-based membrane and its application in the biodegradation of atrazine and trifloxystrobin pesticides(Springer, 2025) Uckun, Aysel Alkan; Uckun, Mirac; Akkurt, Seyma; Birhanli, Emre; Bakar, Busra; Ulu, Ahmet; Yesilada, OzferRecently, focus has been placed on various enzyme immobilization applications as effective, eco-friendly, and low-cost methods for the degradation of pesticides in water. Laccases are very effective biocatalysts that are frequently used in environmental remediation applications. In this research, the use of a biocatalyst obtained by immobilizing laccase purified from Trametes trogii on chitosan-polyethylene glycol methyl ether (Lac/CH/MPEG) in the degradation of atrazine (ATR) and trifloxystrobin (TFS) pesticides in water was investigated. The degradation of these pesticides with this synthesized biocatalyst is the first in the literature. Therefore, primarily, the basic physicochemical parameters and mechanical properties of Lac/CH/MPEG prepared before and after immobilization were investigated. Structural analysis and morphological imaging of Lac/CH/MPEG before and after degradation of ATR and TFS were also performed. In the degradation tests, the initial concentrations at which optimum degradation rates were observed for ATR (72%) and TFS (85%) were 1 mg L-1 and 0.5 mg L-1, and the contact times were 24 h and 12 h, respectively. Additionally, the reuse cycles of Lac/CH/MPEG in ATR and TFS degradation were found to be 5 and 6, respectively. These findings showed that TFS was degraded faster and more effectively than ATR. Compared to several biocatalysts in the literature, ours was shown to degrade pesticides more quickly and efficiently. Considering all the findings, it can be concluded that this novel Lac/CH/MPEG biocatalysts is promising, can be applied, and can be successfully used as an alternative agent for quick and efficient degradation of ATR and TFS in water/wastewater.Öğe Immobilization of Trametes trogii laccase on polyvinylpyrrolidone-coated magnetic nanoparticles for biocatalytic degradation of textile dyes(Taylor & Francis Ltd, 2024) Bakar, Busra; Birhanli, Emre; Ulu, Ahmet; Boran, Filiz; Yesilada, Ozfer; Ates, BurhanHigh cost and low operational stability are the most important challenges limiting the possible use of laccase in the removal of textile dyes. To overcome these challenges, in this study, polyvinylpyrrolidone (PVP)-coated magnetic nanoparticles (MNPs) were produced and characterized. To our knowledge, this is the first study to explore the feasibility of immobilizing a Trametes trogii laccase enzyme on Fe3O4/PVP MNPs. The characterization of samples and the successful immobilization of laccase were verified by characterization methods. Besides, the biochemical properties and stability of the Fe3O4/PVP/Lac were evaluated in terms of optimum pH, optimum temperature, thermostability, thermodynamic and kinetic parameters, storage stability, operational stability, and decolorization efficiency of two different textile dyes. The optimum activities were recorded at pH 2.5 degrees C and 30 degrees C. The Fe3O4/PVP/Lac displayed remarkable thermal stability and activation energy for denaturation, enthalpy, Gibbs free energy, and entropy results confirmed the enhanced stability of Fe3O4/PVP/Lac against high temperatures. Meanwhile, the Fe3O4/PVP/Lac retained about 58% of its original activity after seven consecutive reuses, while it retained up to 25% of its original activity after 28 d of storage at room temperature. K-m and V-max for the Fe3O4/PVP/Lac were calculated to be 126 mu M and 211 mu mol/min, respectively. Finally, after 8 and 6 cycles of repeated use, the Fe3O4/PVP/Lac still decolorized 32.34% and 32.23% of Remazol Brilliant Blue R (RBBR) and Indigo Carmine (IC), respectively. As envisioned, this study suggests a promising way to solve the problems of high price and poor operational stability of the enzyme during biocatalytic decolorization of textile dyes in wastewaters.
