Expression of Bacillus ginsengihumi M2.11 bacterial phytase by recombinant Pichia pastoris strains

Abstract

Phytic acid is the main storage form of organic phosphorus. Due to its structural features, phosphorus in phytate is inaccessible for assimilation by animals. Moreover, remaining inaccessible reservoir of phosphorus for animal nutrition, phytic acid is capable of forming insoluble complex salts, which lead to soil and water pollution. Мicrobial enzymes - phytases, capable of decomposing phytic acid to organic phosphorus are being used as feed additives in animal nutrition to solve this problem. Thus, search and development of technologies for the production of enzymes on an industrial scale are the most urgent. Methylotrophic yeast P. pastoris are widely used in biotechnology, as an efficient system for the recombinant proteins expression. They have many advantages, including rapid growth on inexpensive media, a wide range of molecular tools for genetic manipulation in optimizing production processes, they are safe for humans and animals, carry-out many post-translational modifications and produce recombinant proteins intracellularly or extracellularly within a short period of time. It was found that the recombinant P. pastoris strains pPINK-LC-α-MF -phyC, pPINK-HC-α-amyl -phyC, pPINK-LC-α-amyl -phyC, pPINK-HC-α-MF -phyC are able to produce and to secrete B. ginsengihumi bacterial phytase M 2.11 phyC. The maximum activity was observed in the pPINK-LC-α-MF strain – 2.6 (U / mg). Recombinant B. ginsengihumi M 2.11 phytases exhibited high activity in a wide pH range from 2.5 to 9.0. The MF-phyC-HC construction is pH stable. The temperature optimum of all recombinant phytases corresponds to 37 ° C; recombinant phytases retain their activity in the range from -80 to 90C.