Abstract:In this manuscript,the effect of 9 kinds of vitamins on overproduction of L-tryptophan and cell growth were studied and the concentration of vitamins in culture medium was also optimized. The results showed that the cell growth and the synthesis of L-tryptophan were both promoted strongly with the addition of low concentration of inositol and folic acid. Their optimum concentrations were 0.000 2 mg/L,0.2 mg/L,respectively. Adding higher concentration of biotin can significantly promote cell growth and the synthesis of L-tryptophan,the optimum dosage was0.12 mg/L. The synthesis of L-tryptophan was inhibited severely by adding lower concentration of VB6,when the optimal added concentration was 0.8 mg/L,cell concentration and L-tryptophan production have been significantly improved by 11.8% and 27.2% compared with the control,respectively. Adding VB5may slightly improve the yield of the L-tryptophan,the optimal concentration was 0.4 mg /L. Although,adding VB1,VB2,VB3and VC,cell growth was improved strongly,the synthesis of L-tryptophan were inhibited by different degrees.
