Highly fibrous and porous raw material shaped chitin Isolated from oniscus sp (Crustacea)

WOS: 000369326900011Chitin 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

Microbial biofilm activity and physicochemical characterization of biodegradable and edible cups obtained from abdominal exoskeleton of an insect

WOS: 000382341000009A 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

Efficiency of chitosan-algal biomass composite microbeads at heavy metal removal

WOS: 000369195500006A 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.Selcuk University Research Foundation [BAP-14201082]This study presented was supported by Selcuk University Research Foundation (project number: BAP-14201082)

Microfungal spores (Ustilago maydis and U. digitariae) immobilised chitosan microcapsules for heavy metal removal

WOS: 000368096400023PubMed: 26794753Designing 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.Selcuk University Research Foundation [BAP-14201082]This study was funded by the Selcuk University Research Foundation (BAP-14201082)

Hexavalent chromium removal by magnetic particle-loaded micro-sized chitinous egg shells isolated from ephippia of water flea

WOS: 000466621200003PubMed: 30731166Modified 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

Production of magnetic chitinous microcages from ephippia of zooplankton Daphnia longispina and heavy metal removal studies

WOS: 000454537500021PubMed: 30600000This 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.Selcuk University Research Foundation, Turkey [BAP-14201082]This study was funded by Selcuk University Research Foundation, Turkey"(project number: BAP-14201082)

An environmental catalyst derived from biological waste materials for green synthesis of biaryls via Suzuki coupling reactions

WOS: 000378366300026Synthesis of bio-macromolecular supported catalysts has gained much recent attention due to their greener nature. Among the biopolymers, chitosan is widely used as a support material due to its high affinity for metal ions. In this study, chitosan-Ulva sp. (green alga) composite microbeads were prepared as a support material for palladium catalyst. Ulva sp. particles were incorporated into chitosan matrix to enhance the interaction with palladium ions. The catalytic performance of chitosan-Ulva supported Pd(II) catalyst was investigated in the synthesis of biaryls via the Suzuki coupling reaction. All the experiments were conducted without using any solvent under the microwave irradiation, which is also considered as a green technique. This green catalyst exhibited high selectivity and efficiency in the reactions of phenyl boronic acid with different aryl halides in only 4 min at low temperature (50 degrees C). Excellent TON and TOF values were achieved for the catalyst; 4950 and 75000. In addition, the catalyst did not lose its activity even after 8 cycles. It showed high thermal stability (216.8 degrees C) and durability in presence of oxygen. This green catalyst has a potential to be used in pharmacology, medicine and cosmetics. (c) 2016 Elsevier B.V. All rights reserved

Exceptionally high turnover frequencies recorded for a new chitosan-based palladium(II) catalyst

WOS: 000381593700002To be industrially feasible, and applicable in synthesis of fine chemicals, a catalyst has to possess high turnover number (TON) and turnover frequency (TOF). In this study, a new cross-linked chitosan derivative was synthesized by using 2,2'-pyridil as a cross-linking agent. 2,2'-Pyridil cross-linked chitosan was used to as a support material for palladium catalyst. Chitosan-pyridil-based Pd(II) catalyst was tested in the microwave-assisted synthesis of biaryls via Suzuki coupling reactions. The catalyst yielded remarkable TONs of up to 20,000 and TOFs of up to 240,964 by using very low catalyst loading (5 x 10(-3)% mol) in a short reaction time (5 min). The catalyst also showed a better recyclability. (C) 2016 Elsevier B.V. All rights reserved

Green heterogeneous Pd(II) catalyst produced from chitosan-cellulose micro beads for green synthesis of biaryls

WOS: 000380944500021PubMed: 27516263In green catalyst systems, both the catalyst and the technique should be environmentally safe. In this study we designed a green palladium(II) catalyst for microwave-assisted Suzuki C C coupling reactions. The catalyst support was produced from biopolymers; chitosan and cellulose. The catalytic activity of the catalyst was tested on 16 substrates in solvent-free media and compared with those of commercial palladium salts. Reusability tests were done. The catalyst was also used in conventional reflux-heating system to demonstrate the efficiency of microwave heating method. We recorded high activity, selectivity and excellent TONs (6600) and TOFs (82500) just using a small catalyst loading (1.5 x 10(-3) mol%) in short reaction time (5 min). The catalyst exhibited a long lifetime (9 runs). The findings indicated that both green chitosan/cellulose-Pd(II) catalyst and the microwave heating are suitable for synthesis of biaryl compounds by using Suzuki C-C coupling reactions. (C) 2016 Elsevier Ltd. All rights reserved