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Ali Rafik

Institute of Agronomy and Veterinary Medicine, Economie D'Entreprise, Faculty Member

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Address: Agadir, Region de Souss-Massa-Draa, Morocco

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Papers by Ali Rafik

Isolation and characterisation of trypsin from sardinelle ( Sardinella aurita ) viscera

Journal of The Science of Food and Agriculture, 2008

BACKGROUND: In Tunisia, sardinelle (Sardinella aurita) catches totalled about 13 300 t in 2002. D... more BACKGROUND: In Tunisia, sardinelle (Sardinella aurita) catches totalled about 13 300 t in 2002. During processing, solid wastes including heads and viscera are generated, representing about 30% of the original raw material. Viscera, one of the most important by-products of the fishing industry, are recognised as a potential source of digestive enzymes, especially proteases with high activity over a wide range of pH and temperature conditions. This paper describes the purification procedure and some biochemical characterisation of trypsin from S. aurita viscera.RESULTS: Trypsin from the viscera of sardinelle (S. aurita) was purified by fractionation with ammonium sulphate, Sephadex G-75 gel filtration, Sepharose mono Q anion exchange chromatography, ultrafiltration and a second Sephadex G-75 gel filtration, resulting in a 5.42-fold increase in specific activity and 6.1% recovery. The molecular weight of the purified enzyme was estimated to be 24 kDa using size exclusion chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis. The purified enzyme showed esterase-specific activity on N-α-benzoyl-L-arginine ethyl ester (BAEE) that was four times greater than its amidase-specific activity on N-α-benzoyl-DL-arginine-p-nitroanilide (BAPNA). The optimal pH and temperature for enzyme activity were pH 8 and 55 °C respectively using BAEE as a substrate. The trypsin kinetic constants Km and kcat on BAPNA were 1.67 mmol L−1 and 3.87 s−1 respectively, while the catalytic efficiency kcat/Km was 2.31 s−1 L mmol−1.CONCLUSION: Trypsin was purified from sardinelle (S. aurita) viscera. Biochemical characterisation of S. aurita trypsin showed that this enzyme can be used as a possible biotechnological tool in the fish-processing and food industries. Copyright © 2008 Society of Chemical Industry

Cyclodextrin-polymethylhydrosiloxane gel as sensitive membrane for heavy ion sensors

Materials Science and Engineering: C, 1998

Posidonia oceanica (L.) fibers as a potential low-cost adsorbent for the removal and recovery of orthophosphate

Journal of Hazardous Materials, 2011

Adsorption characteristics of phosphorus from aqueous solutions onto phosphate mine wastes

Chemical Engineering Journal, 2011

... In addition, as cited by Jellali et al. [15], the no resolubilisation of heavy metals during ... more

Fasting of Ramadan in peoples with diabetes in Benghazi, Libya: an exploratory study

Libyan Journal of Medicine, 2010

Removal of phosphorus from aqueous solution by Posidonia oceanica fibers using continuous stirring tank reactor

Journal of Hazardous Materials, 2011

Antioxidant and free radical-scavenging activities of smooth hound ( Mustelus mustelus) muscle protein hydrolysates obtained by gastrointestinal proteases

Food Chemistry, 2009

Successful Application of Underbalanced Coiled-Tubing Drilling in Horizontal Short-Radius Re-Entry Well to Enhance Oil Production in Hassi Messaoud Field, Algeria

... and Hani Qutob, James Chopty, Maurizio Arnone, Fritz Schoch, Naiem Barakat, Rashid Khan, Mich... more

Hospital Preparedness and SARS

... and Hani Qutob, James Chopty, Maurizio Arnone, Fritz Schoch, Naiem Barakat, Rashid Khan, Mich... more

Nouveau Document Microsoft Office Word

Isolation and characterisation of trypsin from sardinelle ( Sardinella aurita ) viscera

Journal of The Science of Food and Agriculture, 2008

BACKGROUND: In Tunisia, sardinelle (Sardinella aurita) catches totalled about 13 300 t in 2002. D... more BACKGROUND: In Tunisia, sardinelle (Sardinella aurita) catches totalled about 13 300 t in 2002. During processing, solid wastes including heads and viscera are generated, representing about 30% of the original raw material. Viscera, one of the most important by-products of the fishing industry, are recognised as a potential source of digestive enzymes, especially proteases with high activity over a wide range of pH and temperature conditions. This paper describes the purification procedure and some biochemical characterisation of trypsin from S. aurita viscera.RESULTS: Trypsin from the viscera of sardinelle (S. aurita) was purified by fractionation with ammonium sulphate, Sephadex G-75 gel filtration, Sepharose mono Q anion exchange chromatography, ultrafiltration and a second Sephadex G-75 gel filtration, resulting in a 5.42-fold increase in specific activity and 6.1% recovery. The molecular weight of the purified enzyme was estimated to be 24 kDa using size exclusion chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis. The purified enzyme showed esterase-specific activity on N-α-benzoyl-L-arginine ethyl ester (BAEE) that was four times greater than its amidase-specific activity on N-α-benzoyl-DL-arginine-p-nitroanilide (BAPNA). The optimal pH and temperature for enzyme activity were pH 8 and 55 °C respectively using BAEE as a substrate. The trypsin kinetic constants Km and kcat on BAPNA were 1.67 mmol L−1 and 3.87 s−1 respectively, while the catalytic efficiency kcat/Km was 2.31 s−1 L mmol−1.CONCLUSION: Trypsin was purified from sardinelle (S. aurita) viscera. Biochemical characterisation of S. aurita trypsin showed that this enzyme can be used as a possible biotechnological tool in the fish-processing and food industries. Copyright © 2008 Society of Chemical Industry

Cyclodextrin-polymethylhydrosiloxane gel as sensitive membrane for heavy ion sensors

Materials Science and Engineering: C, 1998

Posidonia oceanica (L.) fibers as a potential low-cost adsorbent for the removal and recovery of orthophosphate

Journal of Hazardous Materials, 2011

Adsorption characteristics of phosphorus from aqueous solutions onto phosphate mine wastes

Chemical Engineering Journal, 2011

... In addition, as cited by Jellali et al. [15], the no resolubilisation of heavy metals during ... more

Fasting of Ramadan in peoples with diabetes in Benghazi, Libya: an exploratory study

Libyan Journal of Medicine, 2010

Removal of phosphorus from aqueous solution by Posidonia oceanica fibers using continuous stirring tank reactor

Journal of Hazardous Materials, 2011

Antioxidant and free radical-scavenging activities of smooth hound ( Mustelus mustelus) muscle protein hydrolysates obtained by gastrointestinal proteases

Food Chemistry, 2009

Successful Application of Underbalanced Coiled-Tubing Drilling in Horizontal Short-Radius Re-Entry Well to Enhance Oil Production in Hassi Messaoud Field, Algeria

... and Hani Qutob, James Chopty, Maurizio Arnone, Fritz Schoch, Naiem Barakat, Rashid Khan, Mich... more

Hospital Preparedness and SARS

... and Hani Qutob, James Chopty, Maurizio Arnone, Fritz Schoch, Naiem Barakat, Rashid Khan, Mich... more

Nouveau Document Microsoft Office Word