Yellowfin tuna (Thunnus albacares) intestinal tissues: a sustainable marine resource for the recovery of alkaline proteases with potential application in detergent formulations and non-aqueous catalysis media

Yellowfin tuna (Thunnus albacares) is one of the most captured species for industrial processing and their viscera usually are considered a waste that represents a low-cost source of proteolytic enzymes. Thus, the stability of crude alkaline proteases extracted from yellowfin tuna intestinal tissues, to several denaturant compounds was evaluated. The proteolytic activity was retained more than 60% at NaCl concentrations of 5 to 15% (w/v) and when the protease extract was incubated with oxidizing (H₂O₂) and surfactant (SDS and Tween 80) agents, the residual enzyme activity was maintained similar to control with no agent (P > 0.05). Also, yellowfin tuna crude alkaline proteases, exhibited around 70% of residual enzyme activity when were incubated in solid and liquid detergents, suggesting its compatibility with the ingredients of commercial formulations of laundry detergents. The crude alkaline proteases were stable after incubation in ethanol, methanol and 2-propanol for 1 h and even for 2 days. The obtained results, suggest that yellowfin tuna viscera can be exploited as a sustainable marine resource for the recovery of enzymes with potential industrial application.