Aplicação de proteases alcalinas das vísceras do tambaqui (Colossoma macropomum) e da carpa (Cyprinus carpio) como aditivo de detergentes em pó

Abstract

Alkaline proteases are commercially important group of enzymes and have a large variety of applications, mainly in the detergent and food industries. The proteases currently uses in the market are serine proteases produced by Bacillus strains, principally. Fish viscera have wide biotechnological potential as a source of digestive proteases. Biotechnology provides a means for transforming such materials usually discarded into valuable produts such as enzymes. The objective of this research was to test if alkaline proteases from fish viscera could be used as an additive in commercially available detergent formulations. Viscera from Colossoma macropomum, the most important native fish for Brazilian aquaculture, and Cyprinus carpio, the second exotic fish in importance for Brazilian aquaculture, were extracted and used as a source of enzyme for this research. The crude extract obtained upon the homogenization of the viscera was submitted to a partial purification with ethanol. The protein content,proteolytic activity of the fractions thus obtained was assessed. The fraction presenting the highest proteolytic activity was further studied (30-70% of ethanol) resulting in 74.9% and 142.4% of protein recovery for tambaqui and carpa, respectively. This fraction was assayed at different temperatures and pH aiming to estimate the conditions for higher proteolysis. Temperarture and pH stability experiments were also carried out. Different commercial lyavailable detergents, surfactants and hydrogen peroxide were used to test the compatibility of these proteases with detergent formulations. The results reveal that these alkaline proteases extracted from C. macropomum show desirable characteristics for its use in laundry industry such as: retention of 73% and 63% of its initial activity in the presence of Surf® and 5% H202, respectively, after 1 hour of incubation at 40ºC. In addition to that it was observed a slight increase of the proteolytic activity in the presence of non-ionic (Tween 20 and Tween 80) and ionic surfactants (Saponin and Sodium cholate). On the other hand, the proteases extracted from the intestine of C. carpio were compatible with the surfactants and oxidants tested butdid not present the same property in the presence of commercially available detergents.