Site-specific mutagenesis high temperature resistant phytase gene TP and expression vector and application thereof

Abstract

The invention provides site-specific mutagenesis high temperature resistant phytase gene TP and an expression vector and application thereof. Amino acid in a specific area in a phytase amino acid sequence is mutated into praline and arginine so as to enable the phytase to have a special stable protein structure. Simultaneously, a gene sequence is optimized to synthesize a phytase gene according to pichia pastoris codon preference and GC content, recombinant plasmids are built and transferred to pichia pastoris, and positive converters are obtained through screening to conduct induction expression to obtain the high temperature resistant phytase. Experiments prove that the phytase obtained through expression of the pichia pastoris can resist high temperature plasmids with the temperature higher than 85 DEG C, and survival rate reaches 85%. Popularization and application of the high temperature resistant phytase have substantial economical benefit and social benefit on development of feed animal husbandry of our country, and simultaneously great ecological benefit can be obtained.

Description

technical field [0001] The invention belongs to the field of molecular biology feed additives, and in particular relates to a site-directed mutation high-temperature-resistant phytase gene TP, an expression carrier and application thereof. Background technique [0002] Phytic acid (phytic acid) is the main storage form of phosphorus in plants, and phytic acid and its salts are the main storage form of phosphorus in crops such as grains, beans, and oilseeds. Due to the lack of corresponding enzymes in the stomach of monogastric animals, phytic acid cannot be hydrolyzed and utilized, which causes a waste of phosphorus sources, and the phosphorus in the unusable phytic acid is directly excreted, resulting in phosphorus pollution of soil and water. In addition, phytic acid can also chelate with mineral elements and protein, so that these nutrients cannot be effectively used, resulting in a reduction in the nutritional value of plant feed. Therefore, phytic acid is also generally...

AI Technical Summary

Problems solved by technology

At present, a key problem in the application of phytase preparations is that the thermal stability of the enzyme has not been well resolved. The high temperature of granulation has greatly damaged the enzyme activity of phytase, although researchers have studied it from different aspects. Many fruitful studies have been carried out on the heat resistance of phytase, such as obtaining heat-resistant phytase by screening strains producing heat-resistant phytase, using protein engineering, and improving production processes, but the obtained phytase Enzyme heat resistance is still not ideal

Images