Extraction and deacetylation process of chitosan from Tachypleus gigas horseshoe crab of Balok and Muar, Peninsular Malaysia

Background: Chitin and chitosan from the exoskeleton of horseshoe crab was reported to have a comparable quality to commercial chitosan. It would become a good alternative for the existing chitosan in the market. Nonetheless, inefficient isolation processes could lead to a waste to this invaluable raw material and incur additional cost. Chitosan isolated from the raw chitin could be affected by the frequency of deacetylation process. At the same time, horseshoe crabs, as known as a living fossil, must be exploited sustainably. Objective: Thus, it is important to determine if a single deacetylation process can satisfy the quality and amount of extracted chitosan from the exoskeleton. Methods: In this experiment, exoskeletons of horseshoe crab were obtained from two different area (Balok in the South China Sea coast and Muar in the Straits of Malacca) and processed through several steps of grinding, deproteinization and demineralization before went through a single and double process of deacetylation using 50% NaOH. FT-IR spectra were analysed to ensure the completion of deacetylation process. Statistical analysis was done using IBM SPSS Statistics Version 22. The data were presented as mean ± standard deviation (SD). The p value was obtained from the independent-samples T-Test analysis with p < 0.05 was considered significant. Results: Percentage of chitin and chitosan isolated does not have a significant difference (p>0.05) between Balok and Muar. Nonetheless, the degree of deacetylation is significantly different (p<0.05) between the study sites despite the insignificant difference between single and double deacetylation processes. Conclusion: The results suggest that a double process of deacetylation would be efficient to produce chitosan from chitin extracted from the horseshoe crab exoskeleton. The yield was significantly higher when using samples from Balok than Muar which could be related to some other factors that should be further investigated

Morphology description of early larval stages of the Asian horseshoe crab, Tachypleus gigas and their exuviae

Young horseshoe crabs undergo ecdysis to grow and leave behind their old exoskeleton, or exuviae, but our knowledge of the morphology of both the exoskeleton and exuviae are scarce. This study aimed to investigate the process through a Scanning Electron Microscope (SEM) approach. The exuviae from the first and second ecdysis of the instars of Tachypleus gigas were collected right away after each molting, carefully dried, and critical-point dried before coated with gold. The same preparation was made to examine the morphological feature for instars. They were then examined with the SEM. All prosomal appendages are in a complete form during the first instar stage. The second instar stage is noted with the presence of the telson. The exuviae from instars 1, and 2 showed consistently the suture opening located along the anterior edge of the prosoma. This suture is absent from the exoskeleton of the larvae. There are notably two hinge pores located at both ends of the hinge which is the central dorsal part that joins the prosoma and opisthosoma which are absent on the intact larvae’s exoskeleton. The findings contribute to further improving the understanding of early growth and ecdysis in this living fossil

Egg hatching success in an Asian horseshoe crab, Tachypleus gigas incubated in different sediment as substrate

Tachypleus gigasis one of the Asian horseshoe crabs facing threats from human exploitation and habitat degradation. This study aimed to determine the effect of using sediment as substrate in the egg incubation procedure. Freshly laid eggs clutches were collected from a nesting beach during the low tide. Eggs were incubated under the treatment of seawater without sediment (T1), with fine sand (T2), coarse sand (T3), and muddy sand (T4) in the laboratory condition for seven weeks to observe the size, colour changes, and hatching success. Sediment was moderately sorted and poorly sorted for T2 and T3, and T4 respectively, which could be caused to the failure of egg development and hatching. Eggs in T1 (without sediment) developed as shown by the significant increase in size (p<0.05) according to week and hatching success was at 27.8%. The egg’s colour was normal for T1, but eggs turned black and rotten for T2, T3, and T4 despite the good maintenance of water parameters (temperature 29.18 +0.57 -29.56 +0.7 oC; salinity 29.4 +0.5 -29.8 +0.8 ppt; dissolved oxygen 6.16 +0.90 -6.64 +0.90 mg/L; pH 7.7 +0.7 -7.9 +0.4) during the incubation period. Further study is needed to verify the association of sediment grains and microenvironment thus improving the incubation protocol in the conservation initiative of this important living fossil.DO

Abstracts of the International Halal Science Conference 2023

This book presents the extended abstracts of the selected contributions to the International Halal Science Conference, held on 22-23 August 2023 by the International Institute for Halal Research and Training (INHART), IIUM, Malaysia in collaboration with Halalan Thayyiban Research Centre, University Islam Sultan Sharif (UNISSA), Brunei Darussalam. With the increasing global interest in halal products and services, this conference is timely. Conference Title:  International Halal Science ConferenceConference Acronym: IHASC23Conference Theme: Halal Industry Sustainability Through ScienceConference Date: 22-23 August 2023Conference Venue: International Islamic University (IIUM), MalaysiaConference Organizer: International Institute for Halal Research and Training (INHART), International Islamic University (IIUM), Malaysi