Fermentation technology for increasing content of glutamic acid

The invention discloses a fermentation technology for increasing content of glutamic acid. The fermentation technology includes following steps: preparing a protein material, preparing a koji and performing hydrolysis. A high-yield glutaminase microorganism is added when the koji preparing process begins or after the koji preparing process beginning, wherein an adding amount of the high-yield glutaminase microorganism is 103-107 per gram of the koji. In the fermentation technology for increasing the content of the glutamic acid, a mixed koji preparing operation is carried out through addition of the high-yield glutaminase microorganism on the basis of a distiller's yeast preparing technology of soybean sauce to obtain a high-glutaminase-content protein koji. A high-umami seasoning sauce, in which the content of the glutamic acid is more than 30g/L, is obtained through naturally sun-treatment or thermal-insulation fermentation in large pots and then through a squeezing process and a heating and filtering proce