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Öğe Changes in physicochemical properties of chitin at developmental stages (larvae, pupa and adult) of Vespa crabro (wasp)(ELSEVIER SCI LTD, 2016) Kaya, Murat; Sofi, Karwan; Sargin, Idris; Mujtaba, MuhammadIt is already known that chitin in a single organism can exhibit huge differences depending on the functions it serves in different body parts, but the alterations in the characteristics of chitin in course of developmental stages of an organism still remain unknown. This study presents findings on how chitin matrix is changing physicochemically through discrete morphological stages - larva, pupa and adult - of an insect (Vespa crabro). Chitin content of the organisms were found to increase gradually as the organism grew; 2.1, 6.2 and 10.3%, with a dramatic increase in chitin deposition (nearly 3 folds) during the instar from larva to pupa. Enzymatic digestion test demonstrated that chitin isolates were close to pure. Chitin isolates were also subjected to thermal pyrolysis and no variations were observed in the thermal stability of the samples. However, it was observed that surface characteristics of chitin changed greatly as the insect grew. (C) 2016 Elsevier Ltd. All rights reserved.Öğe Characteristics of corneal lens chitin in dragonfly compound eyes(ELSEVIER SCIENCE BV, 2016) Kaya, Murat; Sargin, Idris; Al-jaf, Ivan; Erdogan, Sevil; Arslan, GulsinChitin in the compound eyes of arthropods serves as a part of the visual system. The quality of chitin in such highly specialised body parts deserves more detailed examination. Chitin in the corneal (ommatidial) lenses of dragonfly (Sympetrum fonscolombii) compound eyes was isolated by using the classical chemical method. The chitin content of the corneal lenses was determined to be quite high (20.3 +/- 0.85%). The FT-IR analysis showed that corneal lens chitin was in the alpha-form as found in all arthropod species where mechanical strength is required. The surface morphology analysis by scanning electron microscopy revealed that the outer part of corneal lenses consisted of long chitin fibrils with regular arrays of papillary structures while the smoother inner part had concentric lamellated chitin formation with shorter chitin nanofibrils. Chitinase enzymatic digestion studies, elemental analysis results and the degree of acetylation value showed the purity of chitin samples from corneal lens. The maximum degradation temperature value of the corneal lens chitin was observed at 369.2 degrees C. X-ray analysis revealed that corneal lens chitin has high crystallinity index; 96.4%. Identification of chitin found in ommaditia of insect compound eyes can provide insights into insect vision and chitin-based optical material design studies. (C) 2016 Elsevier B.V. All rights reserved.Öğe Chitosan/sporopollenin microcapsules: Preparation, characterisation and application in heavy metal removal(ELSEVIER SCIENCE BV, 2015) Sargin, Idris; Arslan, GulsinUse of natural polymers as biosorbents for heavy metal removal is advantageous. This paper reports a study aiming to design a novel biosorbent from two biomacromolecules; chitosan, a versatile derivative of chitin, and sporopollenin, a biopolymer with excellent mechanical properties and great resistance to chemical and biological attack. Chitosan/sporopollenin microcapsules were prepared via cross-linking and characterised by employing scanning electron microscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis. Sorption performance of the microcapsules and the plain chitosan beads were tested for Cu(II), Cd(II), Cr(III), Ni(II) and Zn(II) ions at different metal ion concentration, pH, amount of sorbent, temperature and sorption time. The adsorption pattern followed Langmuir isotherm model and the sorption capacity of the chitosan/sporopollenin microcapsules was found to be Cu(II): 134, Cd(II): 0.77, Cr(III): 0.99, Ni(II): 0.58 and Zn(II): 0.71 mmol g(-1). Plain chitosan beads showed higher affinity for the ions; Cu(II): 1.46, Cr(III): 1.16 and Ni(II): 0.81 mmol g(-1) but lower for Cd(II): 0.15 and Zn(II): 0.25 mmol g(-1). Sporopollenin enhanced Cd(II) and Zn(II) ions sorption capacity of the chitosan microcapsules. Chitosan/sporopollenin microcapsules can be used in Cd(II) and Zn(II) metal removal. (C) 2015 Elsevier B.V. All rights reserved.Öğe Determination of Bovine Serum Albumin Adsorption Capacity of Newly Obtained Cellulose extracted from Glycyrrhiza glabra (Licorice)(WILEY-HINDAWI, 2018) Mujtaba, Muhammad; Sargin, Idris; Kaya, MuratExploration of biodegradable and renewable composites ingredients is of great importance. Up to now, roots extract of Glycyrrhiza glabra has been used for different medicinal purposes but remaining cellulose-rich residues have not been evaluated for isolation of any green materials like cellulose. Here in this study, cellulose was successfully isolated from the roots of G. glabra by using conventional cellulose extraction method. The obtained product was characterized using FT-IR, XRD, and SEM. FT-IR and XRD analyses confirmed the identity of the product. The crystallinity index of cellulose isolates was calculated from XRD data as 70%. The cellulose content of the roots on dry basis was recorded as 48.5%. Three types of surface morphologies were observed: smooth non-porous surface, surface with fibril bundles, and porous surface having thin cellulose fibrils. In addition, bovine serum albumin (BSA) adsorption capacity of G. glabra cellulose was determined and compared with that of commercial cellulose. Newly obtained cellulose from the roots of G. glabra exhibited a higher affinity for BSA protein at neutral pH. (c) 2016 Wiley Periodicals, Inc.Öğe Differentiations of Chitin Content and Surface Morphologies of Chitins Extracted from Male and Female Grasshopper Species(PUBLIC LIBRARY SCIENCE, 2015) Kaya, Murat; Lelesius, Evaldas; Nagrockaite, Radvile; Sargin, Idris; Arslan, Gulsin; Mol, Abbas; Baran, TalatIn this study, we used Fourier transform infrared spectroscopy (FT-IR), elemental analysis (EA), thermogravimetric analysis (TGA), X-ray diffractometry (XRD), and scanning electron microscopy (SEM) to investigate chitin structure isolated from both sexes of four grasshopper species. FT-IR, EA, XRD, and TGA showed that the chitin was in the alpha form. With respect to gender, two main differences were observed. First, we observed that the quantity of chitin was greater in males than in females and the dry weight of chitin between species ranged from 4.71% to 11.84%. Second, using SEM, we observed that the male chitin surface structure contained 25 - 90nm wide nanofibers and 90 - 250 nm nanopores, while no pores or nanofibers were observed in the chitin surface structure of the majority of females (nanofibers were observed only in M. desertus females). In contrast, the elemental analysis, thermal properties, and crystalline index values for chitin were similar in males and females. Also, we carried out enzymatic digestion of the isolated chitins using commercial chitinase from Streptomyces griseus. We observed that there were no big differences in digestion rate of the chitins from both sexes and commercial chitin. The digestion rates were for grasshoppers' chitins; 88.45-95.48% and for commercial chitin; 94.95%.Öğe Effect of glutaraldehyde cross-linking degree of chitosan/sporopollenin microcapsules on removal of copper(II) from aqueous solution(DESALINATION PUBL, 2016) Sargin, Idris; Arslan, GulsinBio-based sorbents, especially cross-linked chitosan, have been widely used in heavy metal removal. Type of cross-linking agent and degree of cross-linking largely affect metal sorption behaviour of chitosan-based sorbents. This study describes the preparation of chitosan/sporopollenin (CS) microcapsules cross-linked with different amount of glutaraldehyde (GA)/chitosan ratios. The microcapsules were modified by the incorporation of 0.3, 0.9 and 1.5mL of GA solution (in water 25% v:v) for 1.50g of chitosan. A protected cross-linking method was used for the preparation of the CS/GA microcapsules by the reaction of the microcapsules with Cu(II) as the protector. Scanning electron microscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis were employed for the microcapsules characterization. The adsorption performance of the microcapsules was studied for the removal of Cu(II) at different concentration, contact time, amount of adsorbent, temperature and pH. The maximum Cu(II) removal values were 88.9, 100.4 and 80.7mgg(-1) by 0.3, 0.9 and 1.5mL of GA impregnated CS microcapsules, respectively. The equilibrium adsorption isotherm data of the microcapsules exhibited a better fit to the Freundlich isotherm model. Affinity of the CS microcapsules for Zn(II), Cd(II), Ni(II) and Cr(III) in presence of Cu(II) was also investigated. GA/chitosan ratio affected the metal sorption performance and physicochemical properties of the microcapsules. The results revealed that CS microcapsules that were cross-linked with 0.9mL of GA solution had better Cu(II) ion sorption capacity and can be cost-effective sorbents in water treatment.Öğe Efficiency of Ag(0)@chitosan gel beads in catalytic reduction of nitroaromatic compounds by sodium borohydride(ELSEVIER, 2019) Sargin, IdrisMetal-catalysed reduction of nitroaromatic compounds to aniline derivatives is a useful and important synthetic route in many applications. Metallic silver particles have gained much recent interest as efficient catalysts in catalytic reduction of nitroaromatic compounds by sodium borohydride. In the study metallic Ag particles were stabilized on glutaraldehyde cross-linked chitosan gel beads in water by a simple and green thermal treatment. Ag (0)@chitosan gel beads exhibited an excellent catalytic activity in hydrogenation of 4-nitrophenol, 2-nitroaniline, 4-nitro-o-phenylenediamine and 2,4-dinitrophenol when NaBH4 was used as the hydrogen source. The catalytic activity tests were repeated by varying the catalyst dose, NaBH4 concentration, the amount of nitroaromatic compounds and temperature. The reduction reactions were greatly affected by the temperature of reaction medium and the concentration of NaBH4. At elevated temperatures, for example at 43 degrees C, some reduction reactions went to completion in just 8 s. The study revealed that Ag(0)@chitosan gel beads can be used in catalytic reduction of nitroaromatic compounds to anilines by NaBH4. This catalytic system can be tested an alternative to the catalytic systems requiring use of expensive transition metals such as palladium and platinum. (C) 2019 Elsevier B.V. All rights reserved.Öğe Efficiency of chitosan-algal biomass composite microbeads at heavy metal removal(ELSEVIER SCIENCE BV, 2016) Sargin, Idris; Arslan, Gulsin; Kaya, MuratA new chitosan/algal (Cladophora sp.) composite microbead was produced and used in removal of heavy metal ions. Bleached algal biomass was incorporated into the chitosan matrix through cross-linking with glutaraldehyde. Fourier transform infrared spectroscopy analysis demonstrated that bleached algal biomass consisted of mainly cellulosic residues. Scanning electron microscopy images exhibited that algal particles were immobilised in the polymeric matrix. Sorption capacity of the microbeads was determined; Cd(II): 0.240, Cr(III): 1.128, Cu(II): 1.059, Ni(II): 0239 and Zn(II): 0310 mmol g(-1). The microbeads with bleached algal biomass exhibited higher sorption capacity for Cd(II) and Zn(II) ions than the plain glutaraldehyde cross-linked chitosan microbeads, demonstrating that the contribution of the algal biomass to the sorption. Equilibrium, kinetic and thermodynamic evaluation of the experimental data was performed. The findings revealed that chitosan-algal composite microbeads can be used in heavy metal removal. (C) 2015 Elsevier B.V. All rights reserved.Öğe Hexavalent chromium removal by magnetic particle-loaded micro-sized chitinous egg shells isolated from ephippia of water flea(ELSEVIER SCIENCE BV, 2019) Arslan, Gulsin; Sargin, Idris; Kaya, MuratModified chitin and magnetic particles are two important materials widely used in heavy metal removal studies. Loading of magnetic particles into conventional adsorbents has emerged as a recent convenient way to improve the properties of adsorptive materials. Compared to its deacetylated form chitosan, chitin has very limited use in removal of contaminants because of its insolubility in aqueous environments. This study reports an easy way to produce micro-sized chitin and gives details on loading of magnetic particles into micro-sized chitin to enhance the interaction of chitin with heavy metal contaminant; hexavalent chromium Cr(VI). Removal of Cr(VI) ions from the aquatic environments is of high importance considering its detrimental effects on human health. Chitin microcages that had been isolated from the ephippial eggs of Daphnia longispina (crustacean, water flea) were incorporated with magnetic particles. Chitin microcages and magnetic particles-loaded chitin microcages were tested in removal of Cr(VI) under different solution and operational parameters; adsorbent dosage, contact time, Cr(VI) ion concentration, pH and temperature. Magnetic particles-loaded chitin microcages yielded higher Cr(VI) removal performance under all the specified conditions; chitin microcages: 0.77 mmol/g and particles loaded chitin microcages: 1.29 mmol/g. (C) 2019 Elsevier B.V. All rights reserved.Öğe Highly Fibrous and Porous Raw Material Shaped Chitin Isolated from Oniscus sp (Crustacea)(SPRINGER, 2016) Kaya, Murat; Sargin, IdrisChitin was isolated from a crustacean by keeping the original body shape for the first time. The isolation method followed in this study was simple and time and energy saving unlike the labor-intensive classical methods. Chitin samples preserving the original shape were isolated from Isopoda (Oniscus sp.) successfully in a total of 20 min including filtration time. FT-IR, XRD and TGA analysis and chitinase digestion test demonstrated that the chitin was pure, low crystalline (Crystalline index: 51 %) and had low thermal stability (maximum degradation temperature: 328.8 A degrees C). SEM analysis revealed the highly fibrous structure of chitin. The chitin content of the whole body was found significantly higher (29.6 A +/- 4.2 %) than the earlier reports. Interaction of chitin isolates with Bovine Serum Albumin protein were studied at different pH. It was concluded that this three dimensional raw material shaped chitin can be effectively used in any adsorption studies due to 1) highly fibrous and porous nature, 2) low crystallinity and 3) low thermal stability. And also this biodegradable and biocompatible biopolymer can be suggested as a carrier matrix in further studies thanks to its three dimensional shape.Öğe Interactions of bovine serum albumin with humic acid-Cu(II) aggregates in poly(hydroxyethylmethacrylate) cryogel column(ELSEVIER SCIENCE BV, 2016) Sargin, Idris; Arslan, Gulsin; Erzengin, MahmutUnderstanding the interactions of proteins with humic acid in different media is essential for many applications. This paper investigates the interactions of bovine serum albumin with humic acid-Cu(II) complexes in a poly(hydroxyethylmethacrylate) cryogel column. Humic aggregates were immobilized within the cryogenic matrix. Protein sorption studies were conducted at different temperature, ionic strength, protein concentration, pH and flow-rate. Protein adsorption increased at lower pHs (close to the isoelectric point of the protein; 4.7) and higher temperatures but decreased at higher ionic strength and flow-rates. Both electrostatic and hydrophobic interactions played roles in the sorptive behavior of the protein molecules. Isotherm analysis showed the monolayer protein adsorption onto humic molecules immobilized column. (c) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.Öğe Microbial biofilm activity and physicochemical characterization of biodegradable and edible cups obtained from abdominal exoskeleton of an insect(ELSEVIER SCI LTD, 2016) Kaya, Murat; Sargin, Idris; Erdonmez, DemetA contemporary focus in food industry is the use of edible bio-based products with properties such as antimicrobial and biodegradable to replace the synthetic harmful petroleum-based polymers. Among the natural polysaccharides, chitin has generated considerable research interest thanks to its biocompatibility and abundance. This study investigated the production of chitin bio-cups from abdominal exoskeleton of an insect as an alternative to synthetic materials in food processing industry. The physicochemical properties of the obtained chitin and chitosan cups were studied by FT-IR, TGA, XRD and SEM analyses. The purity of the extracted chitin was examined by chitinase digestive test. The microbial biofilm formation on the cups was tested and no growth was recorded for the common food pathogen bacteria (Listeria monocytogenes) and yeast (Candida albicans). Considering the antimicrobial, antioxidant, nontoxic and edible nature of chitin and chitosan, these cups can be suggested as an alternative bioplastic for food protection. Industrial relevance: In recent years much research has focused on the use of nontoxic and edible biopolymers as film and coating material in food industry to eliminate the use of carcinogenic and harmful petroleum products. Among the biopolymers, chitin and its deacetylated form, chitosan, are attracting widespread interest thanks to their nontoxic, biodegradable and edible properties. Here in this study, we investigated the production of chitin bio-cups from abdominal exoskeleton of an insect as an alternative to synthetic materials in food processing industry. (C) 2016 Elsevier Ltd. All rights reserved.Öğe Microfungal spores (Ustilago maydis and U. digitariae) immobilised chitosan microcapsules for heavy metal removal(ELSEVIER SCI LTD, 2016) Sargin, Idris; Arslan, Gulsin; Kaya, MuratDesigning effective chitosan-based biosorbents from unexploited biomass for heavy metal removal has received much attention over the past decade. Ustilago, loose smut, is a ubiquitous fungal plant pathogen infecting over 4000 species including maize and weed. This study aimed to establish whether the spores of the phytopathogenic microfungi Ustilago spores can be immobilised in cross-linked chitosan matrix, and it reports findings on heavy metal sorption performance of chitosan/Ustilago composite microcapsules. Immobilisation of Ustilago maydis and U. digitariae spores (from maize and weed) in chitosan microcapsules was achieved via glutaraldehyde cross-linking. The cross-linked microcapsules were characterised using scanning electron microscopy, FT-IR spectroscopy and thermogravimetric analysis. Sorption capacities of chitosan-U. maydis and chitosan-U. digitariae microcapsules were investigated and compared to cross-linked chitosan beads: Cu(II): 66.72, 69.26, 42.57; Cd(II): 49.46, 53.96, 7.87; Cr(III): 35.88, 49.40, 43.68; Ni(II): 41.67, 33.46, 16.43 and Zn(II): 30.73, 60.81, 15.04 mg/g, respectively. Sorption experiments were conducted as a function of initial metal ion concentration (2-10 mg/L), contact time (60-480 min), temperature (25,35 and 45 degrees C), amount of the sorbent (0.05-0.25 g) and pH of the metal solution. The microcapsules with spores exhibited better performance over the plain chitosan beads, demonstrating their potential use in water treatment. (C) 2015 Elsevier Ltd. All rights reserved.Öğe Preparation and characterisation of biodegradable pollen-chitosan microcapsules and its application in heavy metal removal(ELSEVIER SCI LTD, 2015) Sargin, Idris; Kaya, Murat; Arslan, Gulsin; Baran, Talat; Ceter, TalipBiosorbents have been widely used in heavy metal removal. New resources should be exploited to develop more efficient biosorbents. This study reports the preparation of three novel chitosan microcapsules from pollens of three common, wind-pollinated plants (Acer negundo, Cupressus sempervirens and Populus nigra). The microcapsules were characterized (Fourier transform infrared spectroscopy, thermo-gravimetric analysis, scanning electron microscopy and elemental analysis) and used in removal of heavy metal ions: Cd(II), Cr(III), Cu(II), Ni(II) and Zn(II). Their sorption capacities were compared to those of cross-linked chitosan beads without pollen grains. C. sempervirens-chitosan microcapsules exhibited better performance (Cd(II): 65.98; Cu(II): 67.10 and Zn(II): 49.55 mg g (1)) than the other microcapsules and the cross-linked beads. A. negundo-chitosan microcapsules were more efficient in Cr(III) (70.40 mg g (1)) removal. P. nigra-chitosan microcapsules were found to be less efficient. Chitosan-pollen microcapsules (except P. nigra-chitosan microcapsules) can be used in heavy metal removal. (C) 2014 Elsevier Ltd. All rights reserved.Öğe Production of magnetic chitinous microcages from ephippia of zooplankton Daphnia longispina and heavy metal removal studies(ELSEVIER SCI LTD, 2019) Sargin, Idris; Arslan, Gulsin; Kaya, MuratThis is the first study on production of three dimensional chitinous microcages from ephippial eggs of a microcrustacean, Daphnia longispina (water flea) by keeping the original shape of its chitinous structure. Iron-based magnetic particles were successfully loaded into the chitinous microcages to enhance its heavy metal sorption capacity. The FT-IR, SEM-EDX and TGA analysis proved the purity of chitin and demonstrated that the loading of magnetic particles into the chitinous microcages was achieved. These newly obtained three-dimensional chitin microcages and magnetic particles loaded microcages were tested in Cd(II), Cr(III), Cu(II), Ni(II) and Zn(II) removal from aqueous solutions. Magnetic particles loaded microcages exhibited a better performance in removal of Cd(II), Cu(II) and Ni(II) ions; while unloaded microcages showed a higher affinity for Cr(III) and Zn(II). This study demonstrated that the chitin microcages are suitable carriers for iron-based magnetic particles. Here these new materials were studied only for removal of five heavy metal ions but these promising materials have a potential to be used in various fields.
