Chitosan Isolated from Horseshoe Crab Tachypleus gigas from the Malay Peninsula

Abstract

Chitosan that was isolated from horseshoe crabs, Tachypleus gigas, for this study were from estuary area in Balok Pahang (East coast) and Muar Johor (West coast) of the Malay Peninsula. The isolation of chitosan was carried out by chemical processes involving deproteinization, demineralization and deacetylation. Physicochemical properties and antibacterial activity were analysed to determine its potential commercialization. The degree of deacetylation (DD) was higher for samples from Balok than Muar (42.4% and 35.2% respectively), but lesser than the commercial grade. There was no significant difference (p>0.05) in the physicochemical properties but obviously they had lesser moist (1.11±0.22 -1.25±0.13%), higher ash content (1.99±0.06 -2.37±0.07%), and low in its solubility (58.00±9.63 -61.70±1.35%) as well as viscosity (52.52±5.38 -64.37±4.73 cP) if compared with commercial chitosan. Chitosan from both field sites also showed great antibacterial activities which concentration dependent against Staphylococcus aureus and Eschericia coli.

A New Marine Biomaterial: The Shell of Mangrove Horseshoe Crabs, Carcinoscorpius rotundicauda (Latreille, 1802) Emphasizing Its Physico-Chemical Characteristics

“…(Edgecombe and Legg, 2014;Giribet, 2018). Kassim et al (2018) reported that horseshoe crabs (Carcinoscorpius rotundicauda) have a bodyforming and protective shell with a strong elastic structure. It is formed by the evolutionary process of the hardened material (Joffe et al, 1975).…”

“…Chen et al (2008a) described that a shell of horseshoe crabs consists of 50-60 nm chitin fibers arranged in parallel and layers (nanofibers of chitosan layers). Characteristics of functional groups in the shells of horseshoe crabs show that the shells consist of hydroxyl groups, secondary amides, asymmetric C-H, C-H alkanes, C=O secondary amides and C-aliphatic ether (Kassim et al, 2018). Briefly, the arthropods exoskeleton consists mainly of chitin and is multifunctional, such as supporting the body, resisting mechanical loads, protecting harsh environmental conditions and resistance to desiccation (Neville, 1975;Vincent, 1991Vincent, , 2002Vincent and Wegst, 2004;Sanchez et al, 2005;Meyers et al, 2008).…”