title: Recovery of proteolytic and collagenolytic activities from viscera by-products of rayfish (Raja clavata).
abstract: The aim of this work was to study the recovery of proteolytic and collagenolytic activities from rayfish (Raja clavata) viscera wastes. Initially, different parts of the gastrointestinal tract by-products (stomach, duodenum section including pancreas, final intestine) were evaluated. The extracts from proximal intestine yielded the highest values of both enzymatic activities. Optimal conditions for protease activity quantification were established at pH = 6, T = 40 degrees C and incubation time < or =20 min. The mathematical equation used to model the joint effect of pH and temperature led to maximum activity at pH = 8.66 and 59.4 degrees C, respectively. Overcooled acetone was found to be best option for recovery of enzymatic activities in comparison with ethanol, PEG-4000, ammonium sulphate and ultrafiltration system. Finally, a simple and systematic protocol of partial purification and total recovery of proteases and collagenases was defined.
authors.affiliation: Grupo de Reciclado y Valorización de Materiales Residuales, Instituto de Investigacións Mariñas (CSIC), r/Eduardo Cabello 6, Galicia, Spain. recicla@iim.csic.es
authors.forename: Miguel Anxo
authors.initials: MA
authors.lastname: Murado
authors.forename: María del Pilar
authors.initials: Mdel P
authors.lastname: González
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Vázquez
mesh_terms: D000818:Animals; D017364:Collagenases / Q000302:isolation & purification*; D003470:Culture Media; D005285:Fermentation; D041981:Gastrointestinal Tract / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007220:Industrial Waste; D010447:Peptide Hydrolases / Q000302:isolation & purification*; D012860:Skates, Fish; D013696:Temperature
chemical_list: D003470:Culture Media; D007220:Industrial Waste; D010447:Peptide Hydrolases; D017364:Collagenases