Abstract: A strain of Yarrowia lipolytica（ZY-4）which producing α-ketoglutaric acid（KGA）was treated for mutation by UV and NTG. Mutation strains which could accumulate much more KGA were obtained. Culture medium for mutation strain on KGA fermentation was also studied. The concentration of KGA accumulated by UV mutation strain and NTG mutation strain increased 67.8% and 110% respectively compared with original strain. The optimal fermentation medium contains glycerol 8%, NH₄Cl 5.0 g/L, thiamine 1.0 μg/L, KH₂P0₄ 1.0 g/L and MgSO₄·7H 2O 0.5 g/L. The production of KGA increased 232.4% after optimization when compared to the original strain.

Key words: α-ketoglutaric acid, Yarrowia lipolytica, Mutantion Breeding