phytase

Phytase is an enzyme that catalyzes the stepwise hydrolysis of phytic acid (myo-inositol hexakisphosphate), releasing inorganic phosphate and producing lower inositol phosphates. Phytic acid is the principal storage form of phosphorus in many plant seeds and plays a role as an anti-nutrient by chelating minerals and reducing their availability.

Natural occurrence and role: Phytases occur in a variety of organisms, including plants, seeds during germination, and many microorganisms. In seeds, phytase activity helps mobilize stored phosphorus for seedling growth. In animal nutrition, monogastric animals such as pigs and poultry lack sufficient endogenous phytase, so dietary phytase is added to improve phosphorus digestibility and reduce phosphorus excretion.

Industrial production and sources: Commercial phytases are produced mainly by fermentation using fungi such as Aspergillus niger and Aspergillus oryzae, as well as by bacteria such as Bacillus spp. They are applied as feed enzymes and as processing aids in food and beverage production. Enzymes are available in liquid or powder forms and are often formulated to withstand processing conditions.

Applications and benefits: In animal feeds, phytase improves the bioavailability of phosphorus, often reducing the need for inorganic phosphate supplements and lowering environmental phosphorus pollution from agriculture. In human foods, phytase can be added to cereals and legumes to decrease phytic acid content, enhancing mineral bioavailability and improving secretion of minerals such as iron and zinc.

Characteristics and regulation: Phytases are typically measured in phytase units (FTU), defined as the amount releasing 1 µmol of phosphate per minute under specified assay conditions. Enzymes differ in pH and temperature optima and in stability, influencing their suitability for different applications. Regulatory status varies by region, but phytase products used as feed additives are widely approved where supported by safety assessments.