Broad-spectrum, high-temperatur-resistant, high-specific-activity phytase, and its coding gene and expression

Abstract

The invention provides a kind of broad-spectrum embedded acid enzyme and its coding gene. The invention also provides the expressing carrier and the recomposing yeast cell which contains the carrier. In the invention, the expressing quantity of embedded acid enzyme in recomposing yeast reaches to 520000U / ml ferment liquor.

Description

technical field [0001] The invention relates to a phytase and its coding gene. The invention also relates to an expression vector containing the modified phytase and a recombinant yeast cell containing the expression vector. Background technique [0002] Phosphorus is an essential mineral that all animals need for growth. Phosphorus accounts for more than a quarter of the total minerals in an animal's body, and 80% of it exists in the bones in the form of hydroxyapatite. Bones serve not only as the skeleton of the body, but also as a storehouse of calcium, phosphorus, and other minerals that can be mobilized to other tissues when needed. The other 20% of phosphorus exists in muscle, blood and other cartilage tissues. They are the constituents of many organic compounds and participate in almost every physiological and biochemical reaction required by life in the body. Because phosphorus has such important biological functions, it is very important to provide adequate phosp...

AI Technical Summary

Problems solved by technology

[0004] Phytate phosphorus is the basic storage form of phosphorus and inositol in the seeds of crops such as cereals, beans and oilseeds, with a content of up to 1-5% (Lolas M.Et al. Food Sci.42:1094-1097, 1977). It accounts for 60-80% of total phosphorus in plants (Nelson T.S.Poultry Sci.47:862-871, 1967). However, phosphorus in the form of phytate phosphorus is difficult to be utilized due to the lack of enzymes that can decompose phytic acid in monogastric animals (Cromwell G.L.Biotechnology in the Feed Industry, Lyons T.P.ed.AlltechTechnical Publication, Nicholasville, KY, 133-145), its utilization rate is only in 0-40%

[0005] Phytate phosphorus cannot be effectively utilized by monogastric animals, which causes many problems in the feeding process. First, it causes waste of phosphorus sources

On the one hand, the phosphorus source in the feed cannot be effectively utilized; on the other hand, in order to meet the animal’s demand for phosphorus, additional inorganic phosphorus must be added to the feed, which increases the feed cost

In actual production, when inorganic phosphorus is added, it often causes animal poisoning due to residual elements such as fluorine and heavy metals in inorganic phosphorus

Second, the formation of high phosphorus feces and pollution of the environment

Third, phytate phosphorus is also an anti-nutritional factor, which will combine with various metal ions Zn during the digestion and absorption process in the gastrointestinal tract of animals. 2+ , Ca 2+ 、Cu 2+ , Fe 2+ etc. and protein sequestration into corresponding insoluble complexes, thereby reducing the effective utilization of these nutrients by animals (Sharma C.B.et al., Phytochemistry.17:201-204, 1978).

The enzymatic activity of this phytase must strictly depend on the high concentration of Ca 2+ The existence of its application prospects is limited

At the same time, it is basically inactive below pH 6.0 and cannot be used in monogastric animal feed

So far, there is no report of a broad-spectrum pH phytase with high enzymatic activity in both acidic and neutral environments

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