Escherichia coli fermentation solution

Selection of culture medium:

LB culture medium (seed culture medium): 5g tryptone, 2.5g yeast powder, 5g NaCl, dissolved in 500ml H2O, adjusted to pH 7.0 with NaOH, packaged in a 2L conical flask, sterilized in a hot and humid autoclave at 121 ℃ for 20 minutes, and stored at room temperature

TB medium (fermentation medium): 240g tryptone, 480g yeast powder, 80g glycerol, 1ml defoamer, dissolved in H2O, diluted to 19L, B. Braun fermenter sterilized in place at 121 ℃ for 15min

Prepare seed solid culture medium: 100mL, divide into test tubes, sterilize at 0.1MPa for 20 minutes, and then place on a slope.

Prepare seed culture medium: 1200mL, evenly divided into three 500mL triangular flasks, sterilized as above.

Cultivation method:

The fermentation of Escherichia coli mostly adopts fed batch cultivation, which is an optimized method in modern fermentation technology and can effectively optimize the chemical environment during the microbial cultivation process. Ensure that microorganisms are in the optimal growth environment. On the one hand, this approach can avoid substrate inhibition caused by excessive initial concentrations of certain nutrients, and on the other hand, it can prevent restrictive nutrients from being depleted and affecting cell growth and product formation. Feeding batch cultivation has been widely used in the fermentation production of various primary and secondary biological products and proteins.

Excessive nutrient content in the culture medium can inhibit cell growth. The use of flow feeding is an effective way to increase cell concentration and exogenous protein production. High density culture regulates cell growth by adjusting the flow rate of restrictive substrates.

Cultivation conditions:

1. Temperature: 36~38 ℃

2. PH: 7

3. Mixing rate: 100-200r/min

4. Dissolved oxygen: 20-50%

5. Ventilation: 1:2VVM

6. Vaccination amount: 1-2%

Operation steps:

1. Preparation of bacterial strains

2. Preparation before canning and sterilization of actual cans

3. Fermentation operation

4. Fermentation management

5. Measurement of various biochemical indicators during the fermentation process

6. Supplement materials

7. Put the can in

8. Cleaning