Effects of biosorption parameter: kinetics, isotherm and thermodynamics for Ni(II) biosorption from aqueous solution by Circinella sp.

Circinella sp. was employed as a biosorbent for removal of Ni(II) from aqueous solution. The biosorption kinetics and isotherms were investigated. The effect of several parameters, such as biosorbent dosage, contact time, initial concentration, pH and temperature, on biosorption process was evaluated. The kinetic studies indicated that the biosorption followed pseudo-second order kinetic model. Biosorption behaviour of Ni(II) on Circinella sp. was expressed by both Langmuir and Freundlich isotherms. The equilibrium data fit better to the Langmuir model compared to the Freundlich model in concentration range studied (1.0-3.0 mM). The thermodynamic parameters (\u394G0, \u394H0 and \u394S0) were also determined, and it was found that the Ni(II) biosorption by Circinella sp. was spontaneous and endothermic in nature

Long-Term Outcomes Of Vitrectomy And Internal Limitıng Membrane Peeling For Myopic Foveschisis

INTRODUCTION: To evaluate the long-term results of pars plana vitrectomy (PPV) combined with internal limiting membrane (ILM) peeling in patients with myopic foveoschisis (MF) METHODS: In this retrospective study, the medical records of the patients who underwent PPV combined with ILM peeling due to myopic foveoschisis were examined. The best corrected visual acuity (BCVA) and the change in BCVA were evaluated. Preoperatively fovea detachment (FD), presence of postoperative ellipsoid zone defect (EZD), and preoperative and postoperative central macular thickness (SMC) were evaluated using optical coherence tomography (OCT). RESULTS: Twenty-five eyes of 20 patients were included in the study. The mean preoperative BCVA was 1.41 +- 0.32 logMAR (1.0-1.8 logMAR) and postoperative BCVA was 0.87 +- 0.41 logMAR (0.3-1.8 logMAR). Postoperative visual acuity improved in 20 eyes (80%). Postoperatively, 4 eyes (16%) had no change in visual acuity and 1 eye (4%) had a decrease in visual acuity. The mean CMT was 683.8 µm +- 155.4 and 262.6 µm +- 46.5 preoperatively and postoperatively, respectively. There was a significant decrease in CMT in the first year after surgery when it was compared with the preoperative CMT (p <0.001). In 20 (80%) eyes, foveoschisis was completely resolved anatomically in the first year after surgery. In 5 eyes (20%), there was a decrease in CMT in the OCT, and a partial improvement in the foveoschisis. DISCUSSION AND CONCLUSION: It is concluded that vitrectomy combined with ILM peeling in the treatment of myopic foveoschisis is an effective and reliable surgical method for increasing visual acuity and providing anatomical improvement

Development An Amperometric Microbial-Enzyme Hybrid Cholesterol Biosensor Based On Ionic Liquid MWCNT Carbon Paste Electrode

In this study we report the development of an amperometric cholesterol biosensor based on cholesterol oxidase from Pseudomonas sp. and catalase immobilized in carbon paste electrode (CPE) modified with multiwall carbon nanotubes (MWCNT) and ionic liquid (IL). The working electrode (CPE/MWCNT-IL/Microorganism (MO)-Catalase) was characterized by impedance spectroscopy and cyclic voltammetry at different stages of its construction. This proposed cholesterol biosensor performed linear relationship in the range of 5-600 mu M with a low detection limit of 1.52 mu M. The biosensor showed good sensitivity and high selectivity and it was successfully applied for the measurement of cholesterol levels in lyophilized serum samples.Ege University Research Fund [15 FEN 021]This project was funded by the Ege University Research Fund (project 15 FEN 021)

Characterization and Antimicrobial Activity of Silver Doped Hydroxyapatite Obtained by the Microwave Method

WOS: 000391190600015In this study, silver (Ag) doped hydroxyapatite (HA) was produced by the microwave method and its antimicrobial activity was investigated. The physical, chemical and structural characteristics of the material were determined using multi-purpose X-ray diffractometry (XRD), Fourier transform infrared spectrometry (FTIR), and scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS) apparatus. The amount of silver in the solutions of silver-doped hydroxyapatite obtained were determined with the use of an inductively coupled plasma optical emission spectroscopy instrument (ICP-OES). The minimum inhibition concentration (MIC) of the silver doped hydroxyapatite (Ag-HA) against the test microorganisms was determined by the Broth Microdilution method. It was established that a concentration of 2.09 - 12.25 mu g/ml was effective against gram-negative bacteria (Escherichia coli ATCC 12228, Salmonella typhimurium CCM 5445, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae CCM 2318), and 4.18 - 12.25 mu g/ml was effective against gram-positive bacteria (Staphylococcus aureus ATCC6538-P, Bacillus subtilis ATCC 6633, Enterococcus faecalis ATCC 29212) and the yeast Candida albicans ATCC 10239.Research Foundation of Ege UniversityEge University [09MUH080]We would like to thank the Research Foundation of Ege University for their financial support (Project No 09MUH080)

New fructofuranoside in fruit of Pyrus amygdaliformis Vill.

Akgul, Yurdanur/0000-0002-9165-4864WOS: 000527157900001PubMed: 32299244The new compound 2-O-beta-D-fructofuranosylglycerol was isolated from the hexane residue. Also 2-O-methyl-alpha-fructofuranoside was isolated for the first time from the fruits of Pyrus amygdaliformis Vill. the chemical structure of isolated carbohydrates was identified using NMR, mass spectroscopic technique and literature data. the minimal inhibitory concentrations (MIC) of P. amygdaliformis Vill. hexane, dichloromethane and butanol extracts of fruits were used for testing microorganisms. Hexane extract showed antimicrobial activity against Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis and Salmonella typhimurium with MIC ranging between 25 and 0.39 mg/mL. the most sensitive strain was found to be K. pneumoniae with MIC value at 0.39 mg/mL in hexane extract. [GRAPHICS] .TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [2209A]This work was supported by a Grant 2209A from TUBITAK

Voltammetric determination of epinephrine by White rot fungi (Phanerochaete chrysosporium ME446) cells based microbial biosensor

WOS: 000286904400129PubMed ID: 21115238The lyophilized biomass of White rot fungi (Phanerochaete chrysosporium ME446) was immobilized in gelatine using glutaraldehyde crosslinking agent on a Pt working electrode. The fungal cells retained their laccase activity under entrapped state. The immobilized cells were used as a source of laccase to develop amperometric epinephrine biosensor. The catalytic action of the laccase in the biosensor released an epinephrinequinone as a result of redox activity, thereby causing an increase in the current. The optimal working conditions of the biosensor were carried out at pH 4.5 (50 mM acetate buffer containing 100 mM K(3)Fe(CN)(6)), and 20 degrees C. The sensor response was linear over a range of 5-100 mu M epinephrine. The detection limit of the biosensor was found to be 1.04 mu M. In the optimization and characterization studies of the microbial biosensor some parameters such as effect of fungi and gelatine amount, percentage of glutaraldehyde on the biosensor response and substrate specificity were carried out. In the application studies of the biosensor, sensitive determination of epinephrine in pharmaceutical ampules was investigated. (C) 2010 Elsevier B.V. All rights reserved

Streptomyces sp TEM 33 possesses high lipolytic activity in solid-state fermentation in comparison with submerged fermentation

WOS: 000366740000004PubMed ID: 25285910Solid-state fermentation (SSF) is a bioprocess that doesn't need an excess of free water, and it offers potential benefits for microbial cultivation for bioprocesses and product development. In comparing the antibiotic production, few detailed reports could be found with lipolytic enzyme production by Streptomycetes in SSF. Taking this knowledge into consideration, we prefer to purify Actinomycetes species as a new source for lipase production. The lipase-producing strain Streptomyces sp. TEM 33 was isolated from soil and lipase production was managed by solid-state fermentation (SSF) in comparison with submerged fermentation (SmF). Bioprocess-affecting factors like initial moisture content, incubation time, and various carbon and nitrogen additives and the other enzymes secreted into the media were optimized. Lipase activity was measured as 1.74 +/- 0.0005 U/g dry substrate (gds) by the p-nitrophenylpalmitate (pNPP) method on day 6 of fermentation with 71.43% final substrate moisture content. In order to understand the metabolic priority in SSF, cellulase and xylanase activity of Streptomyces sp. TEM33 was also measured. The microorganism degrades the wheat bran to its usable form by excreting cellulases and xylanases; then it secretes the lipase that is necessary for degrading the oil in the medium.Ege UniversityEge University [2005-FEN-056]This project was supported by Ege University Scientific Research Projects, 2005-FEN-056

Antibacterial Polymeric Coatings with Synthesized Silver Nanoparticles

WOS: 000347715300002By virtue of their small size, nanomaterials have wide applications. Silver nanoparticles were synthesized by a reduction method in this study. Obtained solution was subjected to Ag+ ions and glucose determinations, pH, turbidity, and particle size estimations. Prepared different types of polyurethane composites were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope-energy-dispersive spectroscopy, atomic force microscopy, and scratch testing. The antibacterial activity against Escherichia coli and Staphylococcus aureus has been studied applying an in vitro test. The bactericidal activity for these bacteria cells has been estimated by zone of inhibition on the nutrient agar plates.TEKNOBIM Company (Izmir, Turkey); State Planning Foundation (DPT, Ankara, Turkey)Turkiye Cumhuriyeti Kalkinma Bakanligi; Dokuz Eylul University (Izmir, Turkey)Dokuz Eylul UniversityThe authors are indebted to TEKNOBIM Company (Izmir, Turkey), State Planning Foundation (DPT, Ankara, Turkey) and Dokuz Eylul University (Izmir, Turkey) for financial and technical supports