Science and Technology Production
Congress
Authorship
Date
2011
Publishing House and Editing Place
European Aquaculture Society
Summary
Information provided by the agent in
SIGEVA
Digestive process comprises two phases in stomached fish: a gastric acidic phase and an intestinal alkaline one. In both phases, the proteolytic activities involved are strongly dependent on the actual pH within the gut which, in turn, depends on the composition of the food ingested. Gastric environment are typically subject to large pH oscillations related to the fullness of the stomach; the minimal gastric pH must be low enough to allow i) an efficient activation of the secreted pepsinogen an...
Digestive process comprises two phases in stomached fish: a gastric acidic phase and an intestinal alkaline one. In both phases, the proteolytic activities involved are strongly dependent on the actual pH within the gut which, in turn, depends on the composition of the food ingested. Gastric environment are typically subject to large pH oscillations related to the fullness of the stomach; the minimal gastric pH must be low enough to allow i) an efficient activation of the secreted pepsinogen and ii) a suitable peptic activity (Al-Janabi et al., 1971; Alarcón et al., 1998). Similarly, a high pH within the intestinal lumen is a key factor determining the activity of alkaline proteases like trypsin and chymotrypsin. At the same time, the usual protein concentrations in juvenile feedstuffs are related to a high buffering capacity of the diet and a potential increase in gastric pH (Lawlor et al., 2005). For all these reasons, we have carried out measurements of gastric and intestinal total proteases at optimum and actual gut pH’s throughout the digestive process in order to i) gain an insight into the potentially limiting steps in the digestion of proteins and ii) find ways to alleviate the detected malfunctions in proteolysis.
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Key Words
Sparus aurataProtease activitiesGut pHFish