Enhanced phytase production by Aspergillus niger mutants in solid state fermentation

Abstract

The present research work was conducted to improve the phytase production by genetic alteration of Aspergillus niger with induced mutagenesis using solid state fermentation. Strain improvement was carried out in the presence of ultra violet (UV) irradiation and ethylmethane sulphonate (EMS) [0.5% v/v] treatments for various time intervals. We reported an improved strain of Aspergillus niger designated as UV-3 mutant producing a zone of hydrolysis of about 40 mm, in comparison to wild strain (26 mm). The highest enzyme activity was found to be 547.64 IU/g for UV-3 mutant followed by EMS-4 mutant (492.23 IU/g)compared to wild strain which showed 406.45 IU/g of enzyme activity. There was 1.35 fold increase in phytase production after mutation studies of Aspergillus niger. Phytase was applied as poultry feed additive and given to broiler chickens for 5 weeks. The results exhibited that there was increase in body weight gain (BWG) of chicks for experimental group (2028 g) in comparison to control group (1903 g). Thus, physical and chemical mutagenesis was proved as an effective technique for the improvement of strain and ultimately for enhanced and economical phytase production for different industrial applications.