Extraction, characterization and antimicrobial activity of chitosan from pen shell, Pinna bicolor

Chitosan is a biopolymer discovered abundantly on earth specifically in the exoskeleton of shrimps, crabs and insects. In the present study, isolation and characterization of chitosan from the pen shell Pinna bicolor was carried out. In addition to this, the chitosan acquired from the pen shell was tested for its antibacterial activity against five bacterial strains. The FTIR analysis confirmed the presence of NH out of plane bending (872 cm−1) and C-O-C stretching (1016 cm−1) for chitosan with 59.76% degree of deacetylation. The Micro Raman showed peaks at 1658 cm−1, 1595 cm−1 and at 954 cm−1 corresponding to chitosan. The XRD was able to establish the crystallinity of the chitosan sample with a maximum peak at 29.3°. The elemental analysis of chitosan sample confirmed higher level of carbon (10.75%) when compared to other elements such as nitrogen, hydrogen and sulphur. The antimicrobial activity of extracted chitosan was evident with greater zone of inhibition against Salmonella typhi (20 mm) and least against Shigella dysenteriae. Thus, the present study unravels the properties of chitosan extracted from P. bicolor thereby paving way for its further use in the field of biomedical science and nanotechnology.