Partial characterisation of digestive proteases of the Mayan cichlid Cichlasoma urophthalmus.
Fish Physiol Biochem
; 40(3): 689-99, 2014 Jun.
Article
en En
| MEDLINE
| ID: mdl-24122197
The characterisation of digestive proteases in native freshwater fish such as the Mayan cichlid Cichlasoma urophthalmus provides scientific elements that may be used to design balanced feed that matches with the digestive capacity of the fish. The purpose of this study was to characterise the digestive proteases, including the effect of the pH and the temperature on enzyme activity and stability, as well as the effect of inhibitors using multienzymatic extracts of the stomach and intestine of C. urophthalmus juveniles. Results showed that the optimum activities of the acid and alkaline proteases occurred at pH values of 3 and 9, respectively, whereas their optimum temperatures were 55 and 65 °C, respectively. The acid proteases were most stable at pH values of 23 and at temperatures of 3545 °C, whereas the alkaline proteases were most stable at pH values of 69 and at 2555 °C. The inhibition assays recorded a residual activity of 4% with pepstatin A for the acid proteases. The inhibition of the alkaline proteases was greater than 80% with TPCK, TLCK, EDTA and ovalbumin, and of 60 and 43.8% with PMSF and SBT1, respectively. The results obtained in this study make it possible to state that C. urophthalmus has a sufficiently complete digestive enzyme machinery to degrade food items characteristic of an omnivorous fish species, although specimens showed a tendency to carnivory.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Péptido Hidrolasas
/
Estómago
/
Cíclidos
/
Digestión
/
Intestinos
Límite:
Animals
Idioma:
En
Revista:
Fish Physiol Biochem
Año:
2014
Tipo del documento:
Article
Pais de publicación:
Países Bajos