The invention discloses a volume dissolved
oxygen transfer coefficient staged control method based on a
citric acid metabolic network. The metabolic flow direction is controlled through controlling the dissolved
oxygen of
citric acid at different
fermentation stages, so the yield of the
citric acid is improved. In the whole
fermentation process of the citric acid, seed liquid is inoculated into a
fermentation tank at the
inoculation quantity of 8 percent, the temperature is maintained at 37 DEG C, the
tank pressure is 0.05 MPa, the stirring speed is maintained at 84 rpm / min, and the air introduction quantity is controlled to be maintained to be 40m<3> / min in the fermentation beginning period, about 48m<3> / min in the fermentation medium period (the fermentation is started for about 2 to 3 hours) and 40m<3> / min in the fermentation later period. When the fermentation is carried out for about 58 hours, the
reducing sugar content is detected, and the fermentation can be stopped when the
reducing sugar content is reduced to a value lower than 5 percent. The dissolved
oxygen transfer coefficient staged control is realized through optimizing the air introduction quantity at different fermentation stages, the improvement for improving the citric acid yield based on the
metabolic network is realized, the process is simple and convenient and is easy to operate, the requirement on equipment is low, the
energy consumption is little, and the method can be widely applied to citric
acid production.