POTENTIAL INHIBITORY EFFECTS OF Spirulina platensis ON PROTEASE ACTIVITIES OF Dentex dentex LARVAE AND LIVE FOODS

摘要

Currently, marine fish production depends on fish meal and oil, which are supplied by wild fisheries. In order to reduce the use offish meal and oil resources, there is an urgent need to evaluate alternative protein sources for microdiets of marine fish larvae. Therefore, attention has been focused on the replacement of fish meal by more sustainable and renewable protein sources (Alexis, 1997; Alexis and Nengas, 2001). Spirulina is a sustainably-produced microalgae that can be used to satisfy nutritional requirements. Habib et al. (2008) revealed that Spirulina can be used as a partial supplementation or complete replacement for protein in diets of juvenile fish because it has a balanced composition of amino acids with concentrations of methionine,tryptophan and other amino acids. Larvae of some species (e.g. sea bass and seabream) appear to have high protease activity at an early stage of development (Cahu and Zambonino Infante, 1995; Moyano et al. 1996). Alarcon et al. (1999) hypothesized that the limited utilization of microdiets may be related to partial inhibition of protease activities by feed ingredients. Therefore, protease inhibitions of live foods when co-fed with Spirulina based diets may be important during early life stages of larvae. Until now, a study on the potential inhibitory effects of Spirulina platensis on protease activities of Dentex dentex larvae and live foods is not available. The aim of this study was to determine the potential inhibitory effects of Spirulina platensison protease activities of Dentex dentex larvae and live foods.