Phytase, a feed additive that optimizes the structure of the intestine and enhances the absorption of nutrients in the small intestine

Phytase is a general term for a class of enzymes that hydrolyze phytic acid and its salts to produce inositol and phosphate. As a new type of feed additive, phytase has great application potential in the fields of animal nutrition and environmental protection. The research progress in phytase classification, source, production technology, strategy to improve yield, separation and purification, and application was reviewed, and the development prospect was prospected.

Phosphorus in plant tissues is mainly in the form of phytate sodium, which is difficult to be absorbed by monogastric animals. Moreover, phytic acid molecules can chelate metal ions, which acts as an anti-nutritional factor and inhibits the absorption of nutrients. Phosphorus is not fully utilized, and it is excreted into the water body through animal excretion, which eventually leads to eutrophication of the water body. The fundamental way to solve this cycle of phosphorus is to solve the problem of phosphorus utilization. Therefore, adding microbial phytase to animal feed is gradually being promoted and applied.

In 1996, the FDA confirmed that phytase is safe in food applications and can be used in animal feed. Phytase has become the third largest feed enzyme. But the main problems currently facing are high production cost and low phytase yield. In recent years, there have been many reports on phytase, mainly focusing on isolation, identification, screening of high-yielding bacteria, fermentation processes, and the application of phytase in animal husbandry production. This article mainly reviews the current upstream and downstream technological levels of phytase and their applications, including fermentation types, strain improvement, etc. The downstream technologies include isolation, purification, and end-product applications.

Phytase as a feed additive has been widely used in pig, poultry, and fish feeds. Most studies have found that phytase can release phosphorus in phosphate. At the same time, because it can improve the utilization of different nutrients, phytase from different sources is often used alone or mixed in the field of feed industry. Feed phytase has become the fastest growing category in the industrial enzyme industry and is increasing year by year.

Studies have shown that adding phytase to corn and soybean meal diets can increase phosphorus utilization by 60% and reduce the amount of phosphorus excreted in feces by 50%. Waldroup et al. Reported that about 50% of phytate phosphorus was released by adding phytase to the diet of broilers fed soybean cake. The study of adding phytase to corn-soybean meal diets in broilers has increased the intestinal villi height, mucosal thickness, and intestinal crypt depth of laying hens, thereby optimizing the intestinal structure and enhancing the intestinal absorption of nutrients.