Comparative Analysis of the Expression Efficiency of the Bacterial Phytase Genes in Pichia pastoris Yeast by the Plate Test

Abstract

Comparative analysis of the efficiency of the expression of the Escherichia coli, Obessumbacterium proteus, and Citrobacter freundii phytase genes in Pichia pastoris methylotrophic yeast has been carried out. A simple model with a genetic construct based on the pPICά vector and the plate test with a modified diagnostic medium containing methanol (instead of glucose) and calcium phytate was proposed for the first time in order to assess the expression level. The optimal pH value for the phytase activity was provided by the addition of lactic acid. The highest expression in the studied heterologous genes was shown for the C. freundii phytase gene.