Heterologous expression of yeast and fungal phytases: Developments and future perspectives

293-311The phytases, which hydrolyse inositol hexaphosphate (IP6), are used as animal feed supplements for ameliorating phosphorus availability and assimilation, and mitigating anti-nutrient effects of phytates. Phytases have been reported from several yeasts and fungi. The phytase titres attainable from the wild yeast and fungal strains are very low and, therefore, attempts have been made to clone and overexpress them in heterologous hosts. The enzymes have also been improved by site directed mutagenesis and directed evolution to suit the applications. This review focuses on the progress made so far in cloning and expression of yeast and fungal phytases in heterologous hosts and the research needs