Expression of Pantoea sp. 3.5.1 AgpP Phytase in Three Expression Systems

Abstract

Nowadays, microbial phytases have been widely used as feed additives that increase the bioavailability of phosphorus for monogastric animals. Still, there is an active search for new phytases, development of effective production systems, and study of their properties. In this study, we compared the biochemical characteristics of bacterial histidine acid phytase of Pantoea sp. 3.5.1 produced in three different expression systems: Escherichia coli, methylotrophic yeast Pichia pastoris, and yeast Yarrowia lipolytica. The maximum activity of the recombinant phytase AgpP-P expressed by P. pastoris occurred at pH 4.0, while the pH optimum of the recombinant AgpP-Y phytase expressed by Y. lipolytica is shifted towards more acidic pH 3.0. The recombinant AgpP-P enzyme is stable at pH values ​​from 2.0 to 5.0, while the AgpP-Y remains active at pH values ​​from 3.0 to 7.0; however, at pH above 8.0, the enzyme becomes inactive. The temperature optimum of recombinant AgpP-P phytase corresponded to 50 °С, while the temperature optimum for AgpP-Y was at 45 °С. The recombinant enzymes AgpP-P and AgpP-Y retained activity at temperatures from 4 to 70 °C and from 4 to 60 °C, respectively. Bivalent metal ions at a concentration of 1 mM had the same effect on the activity of recombinant phytases from E. coli, P. pastoris, and Y. lipolytica: Ca2 +, Mg2 +, and Mn2 + ions more than doubled the activity of enzymes, while Co2 + did not affect the activity of phytases, while ions Zn2 +, Cu2 +, and Fe2 + inhibited the activity of enzymes.