Abstract
Problem statement: Solid fish waste is generated from the unwanted parts of fish including heads, tails, fins, frames, offal (guts, kidney and liver) and skin. It accounts for up to 80% of material from production of surimi, 66% from production of fillet and 27% from production of headed and gutted fish. Currently, fish wastes are disposed off in land-based waste disposal systems or at sea generating toxic by-products during the decomposition process. However, fish processing waste can be used to produce commercially valuable by-products, such as chymotrypsin. Approach: A comperehensive review of the literature on the extraction, purification and characeterization of fish chymotrypsin was performed. Results: Chymotrypsin is an endopeptidase secreted by the pancreatic tissues of vertebrates and invertebrates. It has 3 different structures (chymotrypsin A, B and C) varying slightly in solubility, electrophoretic mobility, isoelectric point and cleavage specificity. Only chymotrypsin A and B are found in fish. Compared with mammal chymotrypsin, fish chymotrypsins have similar amino acid composition and molecular weights. Fish chymotrypsins have higher specific activity, especially those from cold-water fish, and low pH and temperature tolerance. The factors affecting the concentration and activity of chymotrypsin in fish are water temperature, fish species, fish age, fish weight and starvation. Chymotrypsin has application in various industries including the food industry, leather production industry chemical industry and medical industry. Conclusion: Extraction techniques for chymotrypsin include: ultra-filtration, ammonium sulphate fractionation precipitation or water-in-oil microemulsions. Purification can be carried out using re-crystallization and gel-filtration, ion-exchange and hydrophobic interaction chromatography. Further studies should focus on the optimization of purifiying chymotrypsin from fish processing wastes.
Highlights
Zhang et al (2005) studied the effect of local chymotrypsin injection on patients with bites from Chinese cobra and the results showed that it had less primeval effect than local injection of antivenom but better effects than other snakebite drugs
The SDS-PAGE consisted of 12% separating gel and 5% stacking gel
The extracted chymotrypsin is mixed with Tris-HCl buffer to make a proteinase sample (Chong et al, 2002)
Summary
Chymotrypsins isolated from fish and animals such as bovine and swine have four major differences: pH stability, temperature stability, enzyme activity and molecular weight their amino acid compositions are still similar Temperature stability: The chymotrypsins isolated from marine fish living in cold environments (carp, rainbow trout, menhaden, anchovy, sardine and Atlantic cod) have higher catalytic activity at low temperature conditions and are more cold stable (but less heat stable) than mammal chymotrypsins (Kristjansson and Nielson, 1992; Ásgeirsson and Bjarnason, 1993; Heu et al, 1995; Castillo-Yañez et al, 2006; Cohen et al, 1981a; Martinez et al, 1988; Raae et al, 1989). Two Amino acids Asn and Gln which exit in Atlantic cod chymotrypsin are absent in anchovy chymotrypsin
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: American Journal of Biochemistry and Biotechnology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
