Method for preparing tryptophan through fermentation

The invention provides a method for preparing tryptophan through fermentation, and belongs to the technical field of fermentation. The method for preparing tryptophan through fermentation comprises the steps of shake flask culture solution preparation, seed culture solution preparation and fermentation culture. The step of preparing the seed culture solution comprises the following steps: inoculating a shake-flask culture solution into a seed culture medium according to the inoculum size of 1.4-1.6% for seed culture at the culture temperature of 35-38 DEG C for 18.6-19.2 hours, the rotation speed of 414-425 rpm, the dissolved oxygen content of 36-38% and the ventilation ratio of 1.1-1.3 vvm, adjusting the pH to 7.1-7.3, and finishing the culture to obtain the seed culture solution; the seed culture medium is prepared from the following components: 46 to 48 g/L of glucose, 11 to 15 g/L of yeast powder, 7.7 to 7.9 g/L of monopotassium phosphate, 3.0 to 3.2 g/L of culture aid, 2.7 to 2.9 g/L of magnesium sulfate