Microbial production of phytases for combating environmental phosphate pollution and other diverse applications

ABSTRACT

Concerns of phosphorus pollution and its impact on environments have driven the biotechnological development of phytases. Phosphoric acid, inositol phosphate, or inositols are produced after hydrolysis of phosphate from phytate, initiated by phytase. Research over the last two decades on microbial phytases has deepened our understanding of their production, optimization, and characterization. Despite the wide availability of phytase producing microorganisms, only a few have been commercially exploited. The current high cost of phytases, inability to withstand high temperatures (>85°C), a limited pH range, and poor storage stability are a major bottleneck in the commercialization of phytases. The development of novel phytases with optimal properties for various applications is a major research challenge. In this paper, recent advances in microbial phytase production, application of tools to optimize higher enzyme production, and characterization of phytases along with potential biotechnological applications are reviewed. Additionally the development of phytase assay methods and functions of phytate and phytate degradation products are discussed.

KEYWORDS:

• Phytic acid
• monogastric animals
• antinutrients
• fermentation
• protein engineering

Acknowledgments

The authors also would like to thank Prof. B. A. Prior (Honorary Research Professor-DUT) for his invaluable suggestions to improve the manuscript.

Funding

The authors greatly acknowledge financial support from the Durban University of Technology, Durban (South Africa) and National Research Foundation, South Africa for this research.