Characterization of chitin from shells of snails (gastropoda: Helix pomatia, Succinea putris, Cepaea hortensis, Viviparus contectus, V. viviparus)

Abstract

Gastropods widespread occurrence is clear evidence of their successful adaptation to different environments. Though the main component of terrestrial snail shell is calcium carbonate, it can contain an array of other compounds. Jeniaux (1965) and Peters (1972) estimated chitin in shell organics of some species molluscs. However, there is no clear evidence of presence of chitin in all mollusc shells (Furuhashi et al., 2009). Chitin polymorphism (α- versus β-chitin) is another important issue. Many researchers believe that all mollusc shells contain β-chitin (Levi-Kalismann et al., 2001; Addadi et al., 2006) and there is still a possibility that some mollusc shells have α-chitin (Evans, Macey & Webb, 1990). In present study chitin from periostracum of Helix pomatia was extracted and characterized by identifying α- and β-chitin. Specimens of snails Helix pomatia were collected by hand – picking in Kaunas city and district (Lithuania) on August and September in 2015 -2016. For chitin extraction demineralization in a 1 M HCl, deproteinization 1 M NaOH and decolorization in 3% NaClO solution were performed. The IR spectra of chitins extracted from Helix pomatia periostracum were evaluated using a Perkin Elmer FTIR spectrometer over the frequency range of 4000–625 cm-1. The surface morphologies of the chitins isolated from H. pomatia periostracum were analyzed by SEM. Results of this study confirmed the presence of chitin in periostracum of H. pomatia, Succinea putris, Cepaea hortensis, Viviparus contectus, V. viviparus and provided new and additional data in characteristic of chitin.