PRODUCTION AND OPTIMIZATION OF PHYTASE IN THE SOLID-STATE FERMENTATION BY ASPERGILLUS NIGER

Background and Aim:Phytase (Myo-inositol hexaphosphate phosphohydrolase) catalyzes the hydrolysis of phytate to inositol phosphates, myo-inositol, and inorganic phosphate. Phytase is widely distributed as an additive in industrial feed production in monogastric animals such as poultry and pig, playing a significant role in increasing the bioavailability of nutrients and reducing the accumulation of phosphorus in the environment. The aim of this study was to investigate the production and optimization of phytase by Aspergillus niger in a solid-state fermentation containing rice bran.Methods:Aspergillus niger PTCC 5010 was obtained from the Iranian Research Organization for Science and Technology (IROST). In this work, design of experiments (DOE) methodology using Response surface was applied to evaluate the influence of carbon sources (maltose and sucrose) and nitrogen sources (yeast extract and peptone) on phytase production. Measurement of the enzyme activity was carried out by measuring optical density at 660 nm.Results:The highest phytase activity (69.21 U/g) was observed in the medium containing 17.83 g/l maltose, 17.05 g/l sucrose, 9.04 g/l yeast extract and 12.24 g/l peptone.Conclusion:Currently, phytase emerges as world s most widely used feed enzyme. In this study phytase production in SSF containing rice bran supplemented with different carbon and nitrogen sources was studied. The results showed that rice bran can be used efficiently as a nutrient source for phytase production by Aspergillus niger.

Keywords:

phytase , rice bran , Aspergillus niger , solid state fermentation