Optimization of phytase production by Aspergillus ficuum in submerged fermentationusingResponse surface methodology

In this research، the culture condition improvement on phytase productionby Aspergillus ficuum PTCC 5288 was investigated using submergedfermentation method in 250 ml shake flask. Four factors which influencing phytase production، including carbon source (glucose) in five level (2، 3. 5، 5، 6. 5 and 8 g/100 mL)، nitrogen source (ammonium sulphate) five levels (1، 2، 3، 4 and 5 g/100 mL)، phosphor source (wheat bran) five levels (1، 2، 3، 4 and 5 g/100 mL)، and fermentation time five levels (48، 120، 192، 264 and 336 hour) were studied. The optimum levels of these significant factors were determined via response surface methodological approach as: 5. 23g/100 mL glucose، 1. 6 g/100 mL ammonium sulphate، 3. 28 g/100 mL glucose wheat branand198. 30 hours. The maximum predicted amount of phytase was 39. 61 U/mL and the produced amount of phytase under these conditions was 40. 21 U/mL، which indicates the efficacy of the model for prediction of phytase production content under different conditions of the medium.