Phytases from microbes in phosphorus acquisition for plant growth promotion and soil health

Phytases are known to be pro-nutritional enzymes hydrolyzing phytate and making associated nutrients, for instance, phosphorus, iron, and zinc, are bioavailable. Phytase is reported in diverse groups of microbes, plants, and animals, but microbial sources are the most promising ones. Many bacterial and fungal strains have been reported as phytase producers from different environments. Phytases are of commercial importance and play a fundamental role in the animal feed industry and in agriculture. The foremost step to evaluate its efficacy as a feed additive, the study of its characteristic properties such as pH and temperature optimum, proteolytic stability and thermostability is important. It is achieved by producing these enzymes using microbes on large scale and purifying it. Many phytase genes from different microbes have been expressed in different hosts for achieving maximum yields and stability. In fact, many transgenic plants with phytase genes from microbes have been also developed that have ability to grow on phytate as only source of phosphorus. This chapter deals with biodiversity of phytase-producing microbes, production methods, and techniques used to purify microbial phytases for maximum product recovery, further also taking into account the molecular biology for maximum yields and maximum utilization of organic phosphorus. Finally, the chapter also highlights the biotechnological applications of phytases.