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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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    Bat guano as new and attractive chitin and chitosan source
    (BIOMED CENTRAL LTD, 2014) Kaya, Murat; Seyyar, Osman; Baran, Talat; Turkes, Tuncay
    Introduction: Chitin is a biopolymer that forms the exoskeleton of arthropods, and is found in the cell walls of fungi. It has a wide range of uses in fields such as cosmetics, pharmacy, medicine, bioengineering, agriculture, textiles and environmental engineering based upon its nontoxic, ecofriendly, biocompability and biodegradability characteristics. Commercially, chitin is obtained from processing the outer skeleton of Crustacea such as shrimp, crab, prawn and crayfish after they have been consumed as food. The study aims to examine the nature of bat guano and to determine if it is a practical source of chitin, which has not been done previously. Results: In this study, the chitin content of dry bat guano samples was found to be 28%. The bat guano, which was collected from Karacamal Cave, came from the bat species Rhinolophus hipposideros. The chitosan yield of this chitin was 79%. The chitin produced from the bat guano was determined to be in the alpha form according to Fourier transform infrared spectroscopy (FTIR) results. The crystallinity of the chitin and chitosan samples was calculated as 85.49 and 58.51% respectively by X-ray crystallography (XRD) experiments. According to scanning electron microscope (SEM) micrographs, the chitin and chitosan structures were shaped like nanofibers. The thermogravimetric analysis (TGA) results showed that both chitin and chitosan had two step weight losses, which are characteristic of these materials. The nitrogen content of the chitin and chitosan was 6.47 and 7.3% respectively according to the elemental analysis results. Conclusions: In this research, it has been observed that bat guano can be considered to be an alternative source of chitin and chitosan to crab, shrimp, crayfish and krill.
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    COMPARISON OF CHITIN STRUCTURES DERIVED FROM THREE COMMON WASP SPECIES (Vespa crabro LINNAEUS, 1758, Vespa orientalis LINNAEUS, 1771 and Vespula germanica (FABRICIUS, 1793))
    (WILEY, 2015) Kaya, Murat; Bagriacik, Nil; Seyyar, Osman; Baran, Talat
    There has been no study on the chitin structure of wasp species. Here, we selected the three most common wasp species belonging to the family Vespidae for chitin extraction and characterization. Chitin was isolated from each wasp species and characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffractometry (XRD), elemental analysis (EA), and scanning electron microscopy (SEM). The chitin contents of Vespa crabro, Vespa orientalis, and Vespula germanica were 8.3, 6.4, and 11.9%, respectively. The crystalline index (CrI) values for the chitin extracted from each species were 69.88, 53.92, and 50%, respectively. The most important finding of the study is that although the same method was used to extract chitin from each of the three wasp species, the degree of acetylation was different: for V. crabro and V. orientalis it was 96.85 and 99.82% ( the chitin was extremely pure), respectively, whereas that for V. germanica the chitin was 79.83%. (C) 2015 Wiley Periodicals, Inc.