Differentiations of Chitin Content and Surface Morphologies of Chitins Extracted from Male and Female Grasshopper Species

January Differentiations of Chitin Content and Surface Morphologies of Chitins Extracted from Male and Female Grasshopper Species Murat Kaya 0 1 Evaldas Leleius 0 1 Radvil Nagrockait 0 1 Idris Sargin 0 1 Gulsin Arslan 0 1 Abbas Mol 0 1 Talat Baran 0 1 Esra Can 0 1 Betul Bitim 0 1 0 1 Department of Biotechnology and Molecular Biology, Faculty of Science and Letters, Aksaray University , 68100, Aksaray , Turkey , 2 Aksaray University, Science and Technology Application and Research Center , 68100, Aksaray , Turkey , 3 Department of Biology, Vytautas Magnus University , 44404 Kaunas , Lithuania , 4 Selcuk University, Faculty of Science, Department of Chemistry , 42075, Konya , Turkey , 5 Selcuk University, Faculty of Science, Department of Biochemistry , 42075, Konya , Turkey , 6 Guzelyurt Vocational School, Aksaray University , Guzelyurt, Aksaray , Turkey , 7 Department of Chemistry, Faculty of Science and Letters, Aksaray University , Aksaray , Turkey 1 Academic Editor: Erjun Ling, Institute of Plant Physi- ology and Ecology , CHINA In 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%. - Scientists have focused on chitin isolation and characterization from crabs, shrimps, crayfish and mushrooms [14]. In recent years, researchers have studied chitin extracted from insects, anthozoans, sponges and small crustaceans (Oniscus asellus, Asellus aquaticus and Gammarus argaeus) [510].These studies mentioned works which were focused on chitin characterization, content evaluation, physicochemical, and the investigation of functional properties. However, some studies were conducted to compare the chitin contents of two components (stipe and pileus) of mushrooms and to compare the chitosan physicochemical and functional properties isolated from crab shells harvested in three different years [11, 12]. Until now, no studies have been conducted on chitin isolation and the characterization in terms of gender (female and male). Chitin (C8H13O5N)n is a natural polysaccharide and is the second most abundant biopolymer after cellulose. Chitin is a long-chain polymer composed of (14)-linked 2-acetamido-2deoxy-b-D-glucose and was isolated from the cell walls of mushrooms for the first time in 1811 by Henri Braconnot [13, 14]. Generally, chitin is found in the exoskeletons of arthropods (crustaceans, insects, myriapods and arachnids), also in the cell structure of algae and yeast, and in the cell walls of fungi [7, 1517]. Naturally, chitin is found in three crystalline polymorphic forms. Within each form there are different orientations of the microfibrils: a-chitin has antiparallel chains, b-chitin has parallel chains, and g-chitin has the mixture of parallel and anti-parallel chains [15, 18]. Chitin and chitin-derived products are attracting great interest because of their wide range of potential applications within biotechnology, medicine and pharmacology, agriculture, cosmetics, and wastewater treatment [14, 16, 19, 20]. Chitin and its derivatives have a wide range of useful biological properties such as non-antigenicity, biocompatibility, biodegradability and non-toxicity [21, 22]. Chitin and its products, mostly chitosan, are functional polysaccharides and their potential applications within various fields are being actively investigated [7]. Recently chitin and its derivatives have found wider applications (i.e., polyelectrolyte properties, gel-forming ability, high adsorption capacity, healthy weight loss pills, and wound healing applications, matrix for immobilization of biomolecules, support for biosensors, heavy metal removal, and removal of radioactive waste) [14, 16, 19, 22]. This has gained attention of many researchers and made them search for new chitin sources. Crab, shrimp and crayfish have been preferred for commercial production of chitin but new chitin sources like insects could be exploited. Orthoptera is the order of insects that includes grasshoppers, crickets, locusts, katydids and their related species. Grasshoppers are widespread throughout the world [23]. Approximately 20 000 described orthopteran species have been acknowledged worldwide up to now [24], but these organisms have been highly ignored with regards to chitin structure. The aim of this study is to reveal the characterization differences in chitin structures isolated from the female and male of the four orthopteran species. The percentage chitin content of grasshoppers was recorded and the physicochemical properties of chitins were determined by FT-IR, elemental analysis, TGA, XRD and SEM. Also, we studied enzymatic (chitinolytic) digestion of the chitins to reinforce the analyses by the aforementioned characterisation tools. Localities of the species are shown in Table 1. No specific permissions were required for these locations. The field studies did not involve endangered or protected species and provide the specific location of your study. The GPS coordinates: Female and male of the species were collected in the same location. Laboratory samples collected in 2003, 2005 and 2006 were used for chitin extraction in this study. The grasshoppers used for this experiment firstly were dried in an oven at a temperature of 50C for 4 days. Later, dried grasshoppers were milled to a powder and then weighed. The chitin extraction from grasshoppers was followed as described by Kaya et. al. [9] with small changes. Briefly, the powder was treated with 4 M HCl solution (50 mL) at 75C for 2 hours to remove minerals and catechols. Later on, the sample was filtered off and the residue was rinsed thoroughly with distillate water. To achieve deproteinization step, the filtrate was treated with 50 mL of 4 M NaOH solution for 20 h at 150C. The mixture was f (...truncated)