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High 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 °C and 30 °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. Km and Vmax for the Fe3O4/PVP/Lac were calculated to be 126 µM and 211 µmol/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. [ABSTRACT FROM AUTHOR]

Addressing water pollution, particularly in the automotive industry's painting processes, is vital due to its significant environmental impact, and the use of photocatalysis, an environmentally friendly and energy-efficient advanced oxidation method, holds promise for removing non-biodegradable organic dyes from wastewater. In this study, the use of semiconductor ZrO2 nanoparticles in the photocatalytic degradation of pollutants in wastewater under UV light was investigated. Zeta potential, Brunauer-Emmett-Teller (BET) surface area and UV-Vis absorption spectroscopy analyzes were performed on the ZrO2 nanoparticle synthesized under optimized experimental conditions. ZrO2 nanoparticles synthesized under the optimized experimental conditions exhibited a high specific surface area (51.793 m²/g). ZrO2 nanoparticles had strong absorption in the visible light region, and the energy band gap was estimated to be approximately 3.062 eV. Photocatalytic activity was evaluated by degradation of methylene blue under UV light (366 nm). The effects of parameters such as the amount of catalyst, concentration and pH of the dye solution, the wavelength of the UV light source used (366 and 254 nm) and the type of test environment on the removal efficiency of methylene blue were investigated. ZrO2 nanoparticles showed high degradation efficiency of 91% in a strong alkaline environment, which may be the result of the facilitated formation of -OH radicals due to the increased concentration of hydroxyl ions. [ABSTRACT FROM AUTHOR]

The present study aimed to immobilize laccase on dry bacterial cellulose (BC) produced by Komagataeibacter xylinus B759 in mulberry pomace waste extract as a low‐cost and natural waste by‐product and to determine the effectiveness of the obtained laccase immobilized BC (Lac/BC) for textile dye decolorization. The highest BC yield obtained after optimization studies was as 1.70 g/L in pH 8.0 medium at 32°C after 15 days. BC and Lac/BC structures were characterized by different instrumental techniques. A transition to more amorphous character was observed with the binding of the enzyme structure. The morphological properties and fiber structure of the BC and enzyme‐linked cellulose structures were examined by SEM and AFM analyses. Obtained Lac/BC pieces were used for the decolorization of Reactive Blue 171 (RB 171) and Reactive Blue 198 (RB 198) diazo dyes during the repeated‐batch process. As a result of using 12 pieces of Lac/BC, 93% and 98% decolorization values were obtained for the RB 171 and RB 198 dyes in the first use, while the color removal was still 83% and 51% at the 8th use, respectively. The results showed that BC produced in a mulberry pomace waste extract can be used for laccase immobilization and Lac/BC is an effective and promising system for textile dye decolorization. [ABSTRACT FROM AUTHOR]

In this study, cotton fibers and untreated cotton fabric structures used in the textile industry were activated and used as yeast immobilization matrix. Cotton and untreated cotton fabric structures immobilized with yeast were characterized by Fourier transform infrared spectroscopy and X-ray spectroscopy techniques for the determination of their immobilization rates. In addition, surface properties and morphological properties of yeast immobilized structures were investigated. Then, yeast immobilized cotton-based structures were used for color removal of Reactive Blue 171 (RB 171) textile dye, which is a serious environmental pollution factor. Very high color removal results were obtained for both raw cotton and untreated cotton fabric samples with yeast immobilized. For yeast immobilized untreated cotton fabrics, dye color removal results were obtained as 55% and 57%, respectively, after 24 h under static and shaking conditions. For raw cotton fibers immobilized with yeast, the RB 171 decolorization efficiency was 76 and 83% dye decolourization results in static and agitated conditions, respectively. As a result, it has been seen that yeast immobilized cotton fibers can be used successfully in the decolourization of reactive textile dyes. [ABSTRACT FROM AUTHOR]

Superhydrophobic and oleophilic modification of commercial acoustic melamine foam (MF) was made in this study. The modification was carried out with chitosan (CHI) and silica particles (SiO2), by using both a layer-by-layer-like approach (LbL) and dip coating technique. Subsequently, 1-octadecanethiol was used as a secondary modification agent. QCM-D, SEM, and FTIR analyses confirmed that the coating was successfully performed. After the modification, the column wall thicknesses increased than that of MF and they ranged from 25% to 48% for modified MF with an LbL-like approach (MMF) and modified MF via dip coating technique (MMFd), respectively. The sorption experiments showed that modified MFs, which had a water contact angle (WCA) above 160°, could sorb several model pollutants (vegetable oil, chloroform, ethanol, and toluene) up to 76-130 times their original weight. It had been determined that MMF protects its open-pore structure better than that of MMFd, which indicated that MF has a more uniform pore structure after modification. Furthermore, after 10 cycles of the sorption and release process, there was no significant change in sorption capacity, and they preserved their mechanical stability and flexibility. [ABSTRACT FROM AUTHOR]

This study aims to optimize the synthesis of semiconductor zirconia (ZrO2) nanoparticles for future photocatalytic applications in degradation of pollutants in wastewater under ultraviolet (UV) light. The synthesis procedure of ZrO2 nanoparticles was optimized by examining the effects of synthesis methods (ultrasound-assisted, hydrothermal method in an autoclave and conventional precipitation), reaction time (2, 6, 10, and 18 h), ambient pH (3, 7, 10, 13), and surfactant type (anionic, cationic, and non-ionic), on the particle size and crystal phase of the nanomaterial. The characterization of the synthesized samples was performed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), high-contrast transmission electron microscopy (HR-TEM), and transmission electron microscope (TEM) analysis. Consequently, to synthesize ZrO2 nanoparticles with the smallest particle size and monoclinic/tetragonal phase, the experimental conditions were optimized as ultrasound-assisted synthesis method, pH 10, and 6 h reaction time without surfactant. Moreover, percentage yield, particle size, crystallinity, monoclinic and tetragonal volumes of ZrO2 nanostructures synthesized under optimized conditions were determined as 39.40%, approximately 9 nm, 46.77, 79%, and 21%, respectively. It has been determined that the particle sizes can be kept under control by controlling the phase composition of ZrO2 nanostructures by optimizing the synthesis parameters. Structural and morphological characterization results can be correlated to the photocatalytic application, showing the potential of this material for the photodegradation of organic dye pollutants. [ABSTRACT FROM AUTHOR]

Copyright of Commagene Journal of Biology is the property of Adiyaman Scientific Research Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bilayer wound dressing systems consisting of various biopolymers have been preferred in biomedical applications due to its enhanced advantages in comparison with conventional systems. The aim of this research was to develop a novel bilayer wound dressing based on gelatin (G) and gellan gum (GG). The bilayer was composed of an upper layer impregnated with antibiotic drug sodium ampicillin and a drug-free lower sponge layer. The bilayer hydrogels were characterized by FTIR, TGA, DSC and SEM analyses including swelling behaviors and hydrolytic degradation tests. To achieve faster healing of the wound by prevention of the bacterial infection, the bilayer hydrogels were developed as antibiotic-releasing vehicles. Herein, release study of sodium ampicillin was performed in PBS to simulate the physiological micro-environment. Additionally, cyto-compatibility tests of L929 fibroblast cells showed the high proliferation and survival through drug-loaded GG and G hydrogels (GG-G-D) after 24h, 48h and 72h incubation. This novel GG-G bilayer hydrogel could be a good candidate as wound dressing. [ABSTRACT FROM AUTHOR]

Nowadays, in the treatment of such fungal infections, antifungal drugs in various forms are one of the most preferred methods. These medications can be in the form of creams and lotions, shampoos, pills, suppositories, powders, or sprays. The dose of the drugs is adjusted according to the type and growth area of the fungus, the severity of the symptoms, and the medical history of the patients. Dressing materials with antifungal properties are an alternative treatment method used for the treatment of fungal skin infections. These covers not only treat fungal infections but also prevent their spread. Within the scope of this study, polyurethane-based wound dressing materials (PU-UDA/PCL) with antifungal properties were developed. Electrospining method was used to produce these dressing materials and the surface area of the wound dressing material was increased, thereby increasing the effect of antifungal property. Polypropylene glycol, glycerol, and catechin as polyol were preferred in polyurethane (PU) synthesis. These structures were polymerized with isophorone diisocyanate and modified with 10-undecenoic acid. Obtained 10-undecenoic acid modified polyurethane (PU-UDA) structures were transformed into wound dressing structure with polycaprolactone (PCL) by electrospinning method. Structural, morphological, and thermal properties of the wound dressing materials were analyzed with different instrumental analysis methods. The antifungal activities of PU-UDA/PCL were tested. Antifungal tests were performed on C. albicans and C. tropicalis. Therefore, PU-UDA/PCL series could be used as an efficient antifungal agent. Finally, it was determined that the obtained 10-undecenoic acid-based polyurethane fibers have a suitable structure and feature for the treatment of many fungal infections. [ABSTRACT FROM AUTHOR]

In the current study, kappa carrageenan (κ-carr) and gelatin (gel) based hemostatic sponges were fabricated for dental applications. The K-carr and gel based dental sponges were characterized by attenuated total reflection-Fourier transform infrared spectroscopy. The morphological properties of the dental sponges were observed by Scanning Electron Microscope analysis. Thermal properties of sponges were evaluated by Thermogravimetric Analysis. The swelling and hydrolytic degradation percentages of the dental sponges were investigated in pH 6.8 to mimic oral saliva. The mechanical properties of the dental sponges were determined and were found to be higher in comparison with the commercial sponge. The sponges reached approximately 95% blood absorption at the end of 45 min. κ-carr and gel based dental sponges did not show cytotoxic effects on the L929 fibroblast cell line in thiazolyl blue tetrazolium bromide cell viability assay. All results suggested that the developed κ-carr and gel based dental sponges demonstrate great potential for dental applications for the future health care materials. [ABSTRACT FROM AUTHOR]

Copyright of Commagene Journal of Biology is the property of Adiyaman Scientific Research Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Adiyaman University Journal of Science & Technology / Adıyaman Üniversitesi Fen Bilimleri Dergisi is the property of Adiyaman University, Institute of Science / Adiyaman Universitesi Fen Bilimleri Enstitusu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this research was to investigate the potential of ampicillin-loaded hydrogels based on polyvinyl alcohol (PVA), hyaluronic acid (HA) and kappa-carrageenan (K-Carr) as an antibiotic-releasing wound dressing. Firstly, the novel polymers (HA-g-K-Carr) were synthesized by grafting of HA onto K-Carr using 4-dimethylaminopyridine/1-(3-dimethylaminopyl)-3-ethyl-carbodiimide hydrochloride as catalyst system via esterification reaction. The characterization of the polymer structure was performed by Fourier transform infrared spectrum (FTIR), proton nuclear magnetic resonance and thermogravimetric analysis. Secondly, PVA/(HA-g-K-Carr) hydrogel with/without loading of ampicillin molecules was formed via freeze–thawing method since PVA/K-Carr and PVA/HA hydrogels were also fabricated as control groups. The hydrogels were subjected to characterizations with FTIR and X-ray diffractometer. PVA/(HA-g-K-Carr) hydrogel demonstrated the highest swelling amount and highest ampicillin release amount reaching an equilibrium value after 480 min rather than the other hydrogels. Also, PVA/(HA-g-K-Carr) hydrogel exhibited inhibition zone against Escherichia coli and Staphylococcus aureus and no cytotoxic effect for L929 cells. All the results showed that PVA/(HA-g-K-Carr) hydrogels are good candidates for wound dressing applications. [ABSTRACT FROM AUTHOR]

This study reports the preparation of poly(sodium-4-styrene sulfonate) (PSS) treated bentonite and clinoptilolite to prevent the agglomeration and sedimentation of these inorganic fillers during the preparation of hydrogel. For this purpose PSS treated fillers were prepared by using various techniques (dip and dry, hydrothermal, one-step ball milling and ultrasonication methods). The most suitable technique for preparing these PSS treated inorganic fillers (abbreviated as BP-dip and CP-dip) was the dip and dry method. BP-dip and CP-dip based polyvinyl alcohol/polyvinylpyrrolidone (PVA/PVP) composite hydrogels were prepared using the freeze/thawing method after the addition of one of BP-dip and CP-dip inorganic fillers in various amounts. The swelling properties, stability behaviors and Rhodamine B (RhB) adsorption of the composite hydrogels were studied. It was found that the swelling degrees of CP-dip and BP-dip based composite hydrogels with 25 mg of filler were higher than that of all other samples. The kinetic mechanism of RhB adsorption process and the related characteristic kinetic parameters were investigated by Pseudo kinetic models. The adsorption kinetics results for RhB adsorption were found best fitted with pseudo-second-order kinetics model. The maximum RhB adsorption capacity was determined to be for PVA/PVP-CP-dip25, which was 3.3 times higher than that of the unfilled PVA/PVP hydrogel. [ABSTRACT FROM AUTHOR]

The antibacterial sponges with high macroporosity, high interconnectivity and high biocompatibility is a significant concern for wound healing applications. In this work, novel Aloe vera (AV) based sponges were developed via subsequent lyophilization with further chemical crosslinking throughout the double network sponges. Single network was composed of gelatin-sodium alginate (G-SA) while the double network using gelatin-sodium alginate- sodium hyaluronate (G-SA-HA) was produced with the addition of hyaluronic acid solution into the gelatin-sodium alginate matrix. Lastly, Aloe vera as the bioactive agent was fabricated throughout the gelatin-sodium alginate-sodium hyaluronate matrix. The AV-based sponges demonstrated large pores with high interconnectivity. The swelling degree of the AV-based sponges were higher than that of G-SA and G-SA-HA sponges. The release of AV from the sponges reached an equilibrium value after 24 h showing a more controlled release at pH 5.5 than at pH 7.4. AV-based sponges showed antibacterial activity against Staphylococcus aureus, Enterococcus faecalis, Streptococcus pneumoniae and Bacillus cereus and displayed any cytotoxicity against Mesenchymal stem cells. [ABSTRACT FROM AUTHOR]

In this study, the effects of starting material types on graphene oxide (GO) are reported with the aim of developing graphene (GR) synthesis. The GOs were prepared from natural graphite (NG) powder and graphite nanoplate (GNp) based on the Hummers method. Two kinds of GR were successfully synthesized using GOs, which were prepared from NG and GNp in the presence of hydrazine and ammonia for 24 h at a 100°C reaction temperature. The synthesized GOs and GRs were characterized by X-ray diffraction (XRD) techniques, Fourier transform infrared, highcontrast transmission electron microscopy (HCTEM), dispersive Raman spectroscopic analyses, and elemental analyses. HCTEM analyses of GOs and GRs exhibited largely folded, convoluted, and entwined GO and GR structures. The XRD and Raman analyses showed that the number of layers of GO1, GO2, GR1, and GR2 were 9.27, 13.53, 4.11, and 5.26, respectively. On the other hand, GR1, prepared from NG powder, showed much higher quality (peak intensities (ID/IG) = 1.53, C/O = 3.64) than GR2, which was prepared from GNp (ID/IG = 1.64, C/O = 3.17). Thus, this study provides a way to produce higher quality GOs and GRs. [ABSTRACT FROM AUTHOR]

The effects of incubation time, temperature, initial pH, and dye concentration on the indigo carmine decolorization activity of Pseudomonas aeruginosa ATCC 10145 and some factors on the decolorization potential of crude laccase enzyme obtained from Funalia trogii ATCC 200800 were comparatively investigated. This bacterium showed effective decolorization activity at all agitation and temperature values. Indigo carmine was greatly decolorized by P. aeruginosa at all pH values except pH 10. A decrease in decolorization activity occurred with increasing dye concentration, but this bacterium effectively decolorized the dye within 24 h. The decolorization process was through microbial metabolism, not biosorption. No decolorization or laccase activity could be obtained by the cell-free intracellular extract or culture filtrate of this bacterium. On the other hand, crude laccase effectively decolorized indigo carmine under highly acidic conditions, especially at pH 3.0 as 57% in 300 seconds. This activity decreased progressively due to the increase in pH values. In a short incubation period and at high temperature values, the crude laccase enzyme removed the color of the dye at 50 °C (56%), 60 °C (45%), and 70 °C (38%). These data are important for improving methods for decolorization of textile dyes used at high temperatures in various industrial applications. [ABSTRACT FROM AUTHOR]

Funalia 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 CuSO4.5H2O 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. [ABSTRACT FROM AUTHOR]