Since the discovery of phytic acid in 1903 and phytase in 1907, extensive research has been carried out in the field of phytases, the phytic acid degradatory enzymes. Apart from forming backbone enzyme in the multimillion dollar-based feed industry, phytases extend a multifaceted role in animal nutrition, industries, human physiology, and agriculture. The utilization of phytases in industries is not effectively achieved most often due to the loss of its activity at high temperatures. The growing demand of thermostable phytases with high residual activity could be addressed by the combinatorial use of efficient phytase sources, protein engineering techniques, heterologous expression hosts, or thermoprotective coatings. The progress in phytase research can contribute to its economized production with a simultaneous reduction of various environmental problems such as eutrophication, greenhouse gas emission, and global warming. In the current review, we address the recent advances in the field of various natural as well as recombinant thermotolerant phytases, their significance, and the factors contributing to their thermotolerance.
Keywords: Aspergillus; Phytases; Phytate; Pichia; Thermostable.