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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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    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.