Industrial fermentation media often use mixed media containing rapid and slow utilization. Carbon source to control bacterial growth and product synthesis

Empirical approach: Determining fermentation according to different metabolic types Process sugar supplement time, sugar supplement amount, sugar supplement method

Kinetic method: control based on kinetic parameters

Fermentation media are generally selected containing fast and slow utilization mixed nitrogen source

Add nitrogen source during fermentation to control its concentration

Use appropriate phosphate concentrations in basal media

Sub-optimal phosphate concentration is often used in antibiotic fermentation (sub-optimal amount: slightly lower than the optimal amount for bacterial growth)

The optimal concentration of phosphate must be combined with the specific local conditions and use The raw materials used were determined experimentally

biothermal

Stir hot

heat of evaporation

radiant heat

Sensible heat

Choose different fermentation temperatures according to different fermentation stages

Adjust the fermentation temperature appropriately according to changes in fermentation conditions

In industrial production, a large amount of fermentation chemicals are released during fermentation. Hot, more cooling is needed

Control different pH ranges according to different stages of the fermentation process range to maximize product output

The optimal pH is determined experimentally

Adjust the composition of the fermentation medium

Feeding

Add pH buffer to fermentation medium

Change fermentation conditions

Add acid and alkali directly

Abnormal decrease in dissolved oxygen

Abnormally elevated dissolved oxygen

Oxygen supply capacity: Improve the driving force of oxygen delivery and liquid volume oxygen Transfer coefficient KLa

Driving force: ΔC = (C*-CL), mainly affected by C*, And C* is mainly affected by temperature, tank pressure, and properties of the fermentation broth. Sound (difficult to change)

KLa: Increase stirring speed, increase ventilation flow rate, reduce Viscosity, etc.

Control the bacterial concentration at the optimal bacterial concentration

Bacteria can be controlled by controlling the concentration of the nutrient matrix body concentration

Adjust the composition of the culture medium and change some fermentation bars or change the fermentation process to control

Use mechanical strong vibration or pressure changes to burst the foam

Install anti-foam propeller

Defoamers reduce the mechanical strength of the foam liquid film or reduce Low liquid film surface viscosity, or both, makes Foam bursts (antifoaming agents are surfactants)