Fungal phytases: characteristics and amelioration of nutritional quality and growth of non-ruminants.

Abstract

Fungal phytases are histidine acid phosphatases, a subclass of acid phosphatases, which catalyse the hydrolysis of phytic acid resulting in the release of phosphate moieties and thus mitigate its antinutritional properties. The supplementation of feed with phytases increases the bioavailability of phosphorus and minerals in non-ruminant animals and reduces the phosphorus pollution due to phosphorus excretion in the areas of intensive livestock production. Although phytases are reported in plants, animals and micro-organisms, fungal sources are used extensively for the production of phytases on a commercial scale. Phytases have been produced by fungi in both solid-state fermentation (SSF) and submerged fermentation (SmF). The fungal phytases are high molecular weight proteins ranging from 35 to 500kDa. They are optimally active within pH and temperature ranges between 4.5 and 6.0, and 45 and 70°C respectively. Phytate degradation leads to amelioration in the nutritional status of foods and feeds by improving the availability of minerals, phosphorus and proteins in non-ruminant animals and human beings and thus mitigates the environmental phosphorus pollution. Our article focuses on the role of fungal phytases in improving nutritional value of foods and feeds with concomitant increase in growth of non-ruminant animals and mitigating environmental phosphorus pollution.