Abstract

The problem addressed by this project is the need to improve feed efficiency in the aquaculture industry, with the use of a supplement that will eliminate the effect of the phytate present in vegetable protein sources contained in fish diets. Salmon and trout are carnivorous fish, naturally adapted to eat food of animal origin. The plant materials are rich in phytate (phytic acid or salt of myo-inositol hexaphosphate), the storage source of phosphorus in plants, which can not be degraded by monogastric animals like fish because they lack phytase, the specific enzyme that catalyzes the release of phosphorus from the phytate. The inclusion of vegetable protein sources in fish diet has resulted that in despite of the presence of phytate (with high phosphorus content not bioavailable), the diet should be supplemented with extra free phosphate, which is one of the highest costs in the formulation of this diet. Another negative consequence is that phytate shows remarkable anti-nutritional capacity for their ability to form insoluble complexes with minerals and proteins, making it impossible to fish the uptake of these minerals and proteins. Additionally, phytate not used (along with complexed minerals and protein) accumulates in the seabed where it is degraded by microorganisms, contributing to the problem of eutrophication favoring pollution episodes and the genesis of explosive growth of algae neurotoxic phenomenon known as red tide. The opportunity to take advantage of this project lies in the non-existence in the world market a product of active phytase with the required characteristics to allow in vivo digestion of phytate in the digestive tract of fish, and the results developed by the team that presents this proposal to have isolated marine microorganisms that grow at temperatures of 14°C in culture media where the only source of phosphorus is phytate, hence its relevance lies in the feasibility of developing functional fish diets with phytase preparation considered active at low temperature and allowing the fish prepare to face situations of stress and disease. The proposed solution to the problem identified is to develop a food supplement for fish that have high levels of active phytase to degrade phytate at temperatures 10-16°C at which fish digest their food, so as converting the diet in a functional type. The state of the art and preliminary results of the research team study suggests the following hypothesis: Microorganisms capable of growing at lower temperatures (10-16 ° C) using as the only source of phytate phosphorus, are able to produce phytase active at these temperatures and the functional properties of this enzyme are compatible with its use as fish food supplement The feasibility of the proposal is based on the results obtained in recent years by the research team presented this proposal, after having isolated the costs of the XIV and X regions, and cultivated under laboratory conditions microorganisms (mo.) expressing phytase active at low temperatures. The product will be developed in three different presentations. The first presentation corresponds to a semi-purified and concentrate phytase extract and, the second the same extract as a powder and third presentation as dry substrate with active enzymes. The direct market which is focused this product is that of producers of fish feed.