Cloning, Codon Optimization, and Expression of Yersinia intermedia Phytase Gene in E. coli

Background: Phytate is an anti-nutritional factor in plants, which catches the most phosphorus contents and some vital minerals. Therefore, Phytase is added mainly as an additive to the monogastric animals' foods to hydrolyze phytate and increase absorption of phosphorus. Objectives: Y. intermedia phytase is a new phytase with special characteristics such as high specific activity, pH stability, and thermostability. Our aim was to clone, express, and characterizea codon optimized Y. intermedia phytase gene in E. coli. Materials and Methods: The Y. intermedia phytase gene was optimized according to the codon usage in E. coli. The sequence was synthesized and sub-cloned in pET-22b (+) vector and transformed into E. coli Bl21 (DE3). The protein was expressed in the presence of IPTG at a final concentration of 1 mM at 30 degrees C. The purification of recombinant protein was performed by Ni2+ affinity chromatography. Phytase activity and stability were determined in various pH and temperatures. Results: The codon optimized Y. intermedia phytase gene was sub-cloned successfully. The expression was confirmed by SDS-PAGE and Western blot analysis. The recombinant enzyme (approximately 45 kDa) was purified. Specific activity of enzyme was 3849 (U.mg(-1)) with optimal pH 5 and optimal temperature of 55 degrees C. Thermostability (80 degrees C for 15 min) and pH stability (3-6) of the enzyme were 56 and more than 80%, respectively. Conclusions: The results of the expression and enzyme characterization revealed that the optimized Y. intermedia phytase gene has a good potential to be produced commercially andto be applied in animals' foodsindustry.