1. Instrumentation and control
Parameters: to be monitored and controlled
Temperature
Pressure
Agitator shaft power
Flowrate
Liquid level
Viscosity
Turbidity pH
Redox potential
Ion concentration DO
Read pages in the text book.

2. Summary of Bioreactor Design and Operation
Modified batch and continuous reactors
- Chemostat with cell recycle
Keep high cell mass concentration in the reactor.
Production of biomass and low-value product
- Fed-batch
Maintain low substrate concentration
Secondary metabolites, prevent catabolite repression
- Multi-stage chemostat reactor
Separate cell growth and product formation
Secondary metabolites, genetically modified cell culture

3. Summary of Bioreactor Design and Operation
Modified batch and continuous reactors
- Chemostat with cell recycle
(qp=0, kd ≈0, X0=0, Monod equation is applied):

4. Summary of Bioreactor Design and Operation
Modified batch and continuous reactors
- Fed-batch
(qp=0, kd ≈0, Monod equation is applied):

5. Summary of Bioreactor Design and Operation
Modified batch and continuous reactors
- Multi-stage chemostat reactor

6. Summary of Bioreactor Design and Operation
Immobilized cell system
Advantages and disadvantages
Operation consideration
agitation and aeration, determination of volumetric mass transfer coefficient kLa,
heat removal, foam, etc.

7. Summary of Bioreactor Design and Operation
Scale up/down: geometric and dynamic similarity:
In scale-up/down of a stirred-tank reactor, the design calculations are as follows:
Determine the scale-up/down factor Dp/Dm
Calculate the dimensions of the prototype (height H and diameter Dt of tanks, impeller diameter Di) by multiplying that of the model with the scale-up/down factor.
- Select criterion related to dynamic properties and keep it constant in both the model and the prototype.
- Determine the parameters such as impeller speed for the scale-up/down reactor.

8. Summary of Bioreactor Design and Operation
Sterilization
liquid: thermal inactivating
1- P0(t)= 1-[1-e-kdt]N0
kd = αe-E0d/RT
From the above equation:
Known N0, T, t, determine Kd, the probability of an unsuccessful sterilization is determined.
Given N0, T, acceptable probability of failure e.g. 10-3, required time can be determined
Higher Kd tends to achieve low probability of sterilization failure. Normally at 121oC.
Kd of vegetative cells > 1010 min-1, spores min-1. The major concern is spores.

9. Summary of Bioreactor Design and Operation
Sterilization
Degradation of important compounds in the medium by thermal inactivating
ln C/C0=-kdt
where C and C0 are concentrations of the component at time t and t=0, respectively.
kd is the degradation rate constant.
kd = αe-E0d/RT
To determine the components remaining active:
the temperature T → determine kd → with known t, determine C.

10. Summary of Bioreactor Design and Operation
Bioreactor Instrumentation and control