Studies on the role of exogenous proteolytic enzymes in digestion processes in fish

Abstract

Studies were carried out on the proteolytic activity of the fry of common carp, rainbow trout, grass carp, and whitefish, as well as on the activity of digestive organs of adult common carp and rainbow trout . Activity of exogenous enzymes in relation to endogenous ones was assessed on the basis of the proteolytic value of fish food and the activity of digestive organs . It was found that the share of proteolytic enzymes of natural food in the digestion process in fish was high . Beginning from a weight of 50-100 g for common carp and 1o g for rainbow trout, the relation between the daily enzymatic ration and the weight of fish indicates the cooperation of an approximately constant amount of exogenous enzymes .

Digestibility of dry matter and nutrients from three ingredients by the carps, Labeo fimbriatus (Bloch, 1795) and Cyprinus carpio Linnaeus, 1758 with a note on digestive enzyme activity

“…Enzymes play an important role in the digestion and utilisation of feed (Dabrowski and Glogowski, 1977) and dietary nutrients influence digestive enzyme activity (Gangadhara et al, 1997;Fountoulaki et al, 2005). In general, the activity pattern of the digestive enzymes corroborated the digestibility pattern of nutrients in the diets in both the species tested.…”

Desenvolvimento do Surubim do Iguaçu (Steindachneridion sp., Garavello (1991)) (Siluroidei:Pimelodiae) em ambiente escuro durante a fase inicial, alimentado com diferentes dietas

“…O tratamento A+R proporcionou o melhor desempenho das larvas, demonstrando a importância da Artemia no início da alimentação exógena, devido ao seu alto valor biológico e pequeno tamanho, o que permita que seja o primeiro alimento ingerido pelas larvas, como constatado por Kossowski (1991 O menor desempenho final das larvas do tratamento Z demonstra que apesar de inicialmente o desenvolvimento ser satisfatório, pelo fato do zooplâncton ser um alimento de alto valor biológico e liberar enzimas proteolíticas (DABROWSKI;GLOGOWSKI, 1977;HERBERT, 1978), com o desenvolvimento das larvas, estas passaram a ter preferência pelos alimentos inertes (UFODIKE; WADA, 1991).…”

Changes in midgut gland morphology and digestive enzyme activities associated with development in early stages of the American lobster Homarus americanus

“…Thus t increased levels of digestive enzymes were presumed to be induced by feeding on living organisms. Dabrowski and Glogowski (1977) have suggested that larval marine fishes require an exogenous source of digestive enzymes from a live, or at least natural, food in order for " enzyme secretion to function properly since initially the gastrointestinal cells were not completely differentiated. Whether a similar induction of specific digestive enzymes by exogenous substrate or enzyme molecules occurs in invertebrate larvae is unknown.…”