Effect of Nutritional Factors on Citric Acid Fermentation by Aspergillus niger

[Objective] The research aimed to study the effects of nutritional factors on citric acid fermentation by Aspergillus niger.[Method] The relationship between citric acid output and nutrients in the fermentation medium was investigated.[Result] Single factor experiments results showed that the best fermentation time of citric acid fermentation was 120 h,the best carbon source was sucrose,and the best nitrogen source was(NH4)2SO4.Orthogonal experiment results showed that the appropriate culture mediums were: Sucrose was 10%,(NH4)2SO4 was 0.4%,MgSO4·7H2O was 0.025%,pH value was 6.0.[Conclusion] The study confirmed the better excellent formula of citric acid fermentation by Aspergillus niger,providing the theoretical basis for effective industry production of citric acid.