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    Antimicrobial and Antioxidant Properties of Ceriodaphnia quadrangula Ephippia Chitosan
    (Ars Docendi, 2016) Asan-Ozusaglam, Meltem; Cakmak, Yavuz Selim; Kaya, Murat; Erdogan, Sevil; Baran, Talat; Mentes, Ayfer; Saman, Ihsan
    The chitosan from ephippia of Ceriodaphnia quadrangula (Crustaceae) has been fully characterized in our previous study, and in this work it was tested for antibacterial and antifungal activities against human and fish pathogens, while also determining its antioxidant activities. Using the disc diffusion method showed that the antimicrobial activity was observed against all tested microorganisms in the range of 12.84 -16.28 mm. The minimal bactericidal concentration (MBC) value was found to be 0.63 - 2.50 mg/ml. Chitosan obtained from C. quadrangula ephippia showed higher antimicrobial activity against some pathogenic bacteria than commercial antibiotics. While chitosan inhibited 35.83% of the 1,1-diphenyl-2-picrylhydrazyl radicals (at 5 mg/ml), it showed an activity of 14.48 mu g/ml for ferrous ion reducing. Consequently, it is suggested that chitosan obtained from the ephippia of C. quadrangula (Crustacea) can be used as food/feed additives, preservatives or in the pharmaceutical industry instead of using synthetic antimicrobials and antioxidants.
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    Characterisation of ?-chitin extracted from a lichenised fungus species Xanthoria parietina
    (Taylor & Francis Ltd, 2015) Kaya, Murat; Halici, Mehmet Gokhan; Duman, Fatih; Erdogan, Sevil; Baran, Talat
    Lichens are symbiotic associations formed mainly by ascomycete fungi and green algae or cyanobacteria. The presence of chitin in the fungal cell wall has been revealed by previous studies. Considering the presence of fungi in the lichens, this work determines the presence of chitin in a cosmopolitan lichen species Xanthoria parietina. In this study, chitin was derived from a lichen species for the first time and its physicochemical properties were determined by Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy and elemental analysis. The dry weight chitin content of X. parietina was 4.23%, and this chitin was in the -form. The crystalline index value of the lichen chitin was calculated as 70.1%. The chitin from X. parietina had a smooth surface.
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    Chitin extraction and characterization from Daphnia magna resting eggs
    (Elsevier Science Bv, 2013) Kaya, Murat; Sargin, Idris; Tozak, Kabil Ozcan; Baran, Talat; Erdogan, Sevil; Sezen, Goksal
    New application areas for chitin and its derivatives have been extensively investigated and there is a solid, growing demand for new chitin sources. In this present study, chitin content of Daphnia magna resting egg (18-21%) was determined for the first time. FTIR, elemental analysis, TGA, XRD and SEM studies revealed the structural and thermal properties of extracted alpha-chitin. This study suggests that D. magna resting eggs can be exploited as an attractive alternative chitin source. (C) 2013 Elsevier B.V. All rights reserved.
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    Comparison of chitin structures isolated from seven Orthoptera species
    (Elsevier, 2015) Kaya, Murat; Erdogan, Sevil; Mol, Abbas; Baran, Talat
    Differences in the physichochemical properties of the chitin structure of the exoskeleton of seven species from four genera were investigated in this study. The same method was used to isolate the chitin structure of the seven species. The physicochemical properties of the isolated chitins were revealed by ESEM, FTIR, TGA and XRD analyses. The FTIR, TGA and XRD results from the chitin samples were similar. The surface morphologies of the chitins were investigated by ESEM and interesting results were noted. While the surface morphologies of the chitins isolated from two species within the same genus were quite different, the surface morphologies of chitins isolated from species belonging to different genera showed similarity. It was determined that the dry weight chitin contents of the grasshopper species varied between 5.3% and 8.9%. The results of molecular analysis showed that the chitins from seven Orthoptera species (between 5.2 and 6.8 kDa) have low molecular weights. Considering that these invasive and harmful species are killed with insecticides and go to waste in large amounts, this study suggests that they should be collected and evaluated as an alternative chitin source. (C) 2014 Elsevier B.V. All rights reserved.
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    A physicochemical characterization of fully acetylated chitin structure isolated from two spider species: With new surface morphology
    (Elsevier Science Bv, 2014) Kaya, Murat; Seyyar, Osman; Baran, Talat; Erdogan, Sevil; Kar, Musa
    Spiders are a huge group which includes more than 44,000 species. But there has been no study of the chitin structure of spiders. In this study we physicochemically characterized chitin structure of two common spider species (Geolycosa vultuosa and Hogna radiata). Chitin content was determined as 8-8.5% for G. vultuosa and 6.5-7% for H. radiata. FTIR, TGA and XRD results showed that the chitin structures are in a-form. Environmental scanning electron microscopy (ESEM) revealed that the surface morphology of each species is different. Chitin yielded from G. vultuosa has two different pore structures. The type one pore is rarely sequenced and its size ranges between 190 and 240 nm, while the type two pore is tightly sequenced and its size ranges between 11 and 32 nm. There is no information in previous studies about the chitin structure with two different pore morphologies. A new chitin surface morphology has been determined in G. vultuosa. The chitin isolated from H. radiata, has classic morphology: nanofibre structures (10-17 nm) and 195-260 nm sized pores. Acetylation degree of the chitin samples was calculated as 97% for G. vultuosa and 99% for H. radiata in accordance with elemental analysis results. (C) 2014 Elsevier B.V. All rights reserved.
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    Physicochemical comparison of chitin and chitosan obtained from larvae and adult Colorado potato beetle (Leptinotarsa decemlineata)
    (Elsevier Science Bv, 2014) Kaya, Murat; Baran, Talat; Erdogan, Sevil; Mentes, Ayfer; Ozusaglam, Meltem Asan; Cakmak, Yavuz Selim
    Chitins and chitosans obtained from larva and adult Coloradopotato beetles (Leptinotarsa decemlineata) were physico-chemically characterized and differences between adults and larvae were identified. The dry weight chitin contents of the adult Colorado potato beetles and larvae were determined as 20% and 7%, respectively. The chitin produced chitosan yields of 72% from the adult Colorado potato beetles and 67% from the larvae. FTIR analysis showed that the isolated chitins were in the alpha form. Crystalline index values, determined by XRD, were 72% for larvae and 76% for adults. The degradation temperatures of the isolated chitin structures were measured by TGA, and this showed that the chitin from adult Colorado potato beetles had a more stable structure than that from the larvae. The surface morphologies of the isolated chitin and chitosan structures were analysed with SEM and it was revealed that these structures consisted of nanofibres. According to elemental analysis, the purity of chitin and chitosan from adults was greater than that from the larvae. The results of molecular analysis showed that the chitosans from adults (2.722 kDa) and larvae (2.676 kDa) of the Colorado potato beetle have low molecular weights. Antimicrobial and antioxidant activities of both adult and larval chitosans were determined. The adult potato beetle is more appropriate than the larvae as an alternative chitin source because of the fact that its dry weight chitin content, chitosan yield and purity of chitin are higher than those from the larvae, and its antimicrobial and antioxidant activities are also higher than those from the larvae. (C) 2014 Elsevier B.V. All rights reserved.
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    Porous and nanofiber ?-chitosan obtained from blue crab (Callinectes sapidus) tested for antimicrobial and antioxidant activities
    (Elsevier, 2016) Kaya, Murat; Dudakli, Fatma; Asan-Ozusaglam, Meltem; Cakmak, Yavuz Selim; Baran, Talat; Mentes, Ayfer; Erdogan, Sevil
    Chitin was isolated using the classical chemical method from the shell of Callinectes sapidus. The chitin content in the dry weight of the crab shells was determined as 12.1%. Total chitosan yield was recorded as 76%. The deacetylation degree of the chitosan was found to be 82.5%. The obtained chitin was in the alpha-form which was confirmed from the results of FTIR, TGA and XRD analyses. Resulting chitin showed DTG max value as 390 degrees C while in same regard chitosan show this value as 306 degrees C. Detailed information about the composition of pores and nanofibers was obtained using SEM. Disc diffusion method used for testing the antimicrobial activity, inhibition zone diameters of the chitosan from C. sapidus varied between 15.28 and 20.21 mm for human bacterial pathogens, between 15.51 and 16.25 mm for fungal pathogens and between 14.22 and 15.75 mm for fish bacterial pathogens, respectively. MBC and MFC values of the chitosan from C sapidus were between 0.16 and 2.50 mg/mL. The results of DPPH and ferric ion reducing power activity used for determining the antioxidant activity of the chitosan, were found as IC50: 5.99 and EC50: 6.16, respectively. (C) 2015 Elsevier Ltd. All rights reserved.