Investigation of citric acid production by A.niger CA6 isolated from Urmia University glasshouse, and optimization carbon, Nitrogen & phosphor sources in submerged fermentation

During this research A.niger CA6 with the ability to produce 34.8 mg/ml citric acid was screened as the best var among 16 microorganisms that was selected among 64 isolated var from soil sample include organic compounds. On the basis of experiments results, the optimum concentration of glucose (as a carbon source) with the production efficiency of 34.5% is 100 g/l. (NH4)2SO4, NH4NO3, NH4PO4 and NaNO3 were used as nitrogen source, and on the basis of experiment results (NH4)2SO4 with concentration equal to 1.5g/l and citric acid production efficiency equal to 35% was known as the best nitrogen source for citric acid production by A.niger CA6.To optimization of type and concentration of phosphor source, we used KH2PO4 and K2HPO4. On the basis of results with the concentration 1gr/lit and production efficiency equal to 35% was distinguished as the best source of the phosphor source.