Liquid Culture Technology（3）

The key technical points of liquid strains mainly lie in the following aspects:
1. Formula
Yeast extract, peptone, soybean meal, corn starch, brown sugar, sucrose, glucose, etc.
The most common raw materials: a combination of soybean meal powder, yeast extract, sucrose, glucose, MgSO4 and K2HPO4
water (purified water)
2. Proportion
Consider C/N
Generally 20~40:1
3. Oil-free, sterile air
Air compressor: screw-type oil-free/micro oil compressor
Gas storage tank: generally 1.5 cubic meters in size
Water removal, oil removal, coarse filtration, drying, temperature control, etc.
Bacterial filter pore size: 0.2 ㎛ (6000 hours)
pressure regulating valve

4. Cleaning, connection and sealing of liquid tanks
Residues (bottom valve, mirror window area)
Is the air filter connected properly?
Whether each pipe is clamped and sealed

5. Preparation
Sieve raw materials (80-120 mesh)
Dissolve in water first and then add to fermentation tank
6. Sterilization
Formula affects sterilization time
Add soybean meal and corn flour – increase sterilization time
Medium is cooked and filtered in advance to reduce sterilization time
7. Cooling
water cooling
Ventilation and anti-negative pressure
8. Vaccination
Reduce opening time
Do not add agar cubes
9.Culture
Zero pressure or slight pressure
Check silicone tube condensation water