In this invention, two phytase genes from two generally-regarded-as-safe microorganisms, Bacillus licheniformis and Bacillus subtilis 168, were cloned and characterized. A process for phytase enzyme over-expression and purification was also developed. The enzymes have molecular weight of about 48 kilodaltons and showed extracellular phytate-hydrolyzing activities. The recombinant enzyme can be used to enhance phytase utilization in various commercial areas, including preparation of animal feed and transgenic plants that have increased growth rates for maturity, flowering and fruiting.