Self-Evaluation

Q1. The dissolved oxygen of pure water at 200°C and 1 Atm pressure is -
       (A)   100 PPM
       (B)   50 PPM
       (C)   25 PPM
       (D)   6 PPM

Q2. 1 vvm of air is passed in a 3-liter bioreactor containing the 2 liter fermentation broth will be equivalent to -
       (A)   3 liters of air per minute
       (B)   2 liters of air per minute
       (C)   6 liters of air per minute
       (D)   1.5 liters of air per minute

Q3. KLa features -
       (A)   Aeration efficiency of dissolution of oxygen in the bioreactor
       (B)   Capacity of fermentation broth to retain oxygen
       (C)   Capacity of the growing culture to take up oxygen
       (D)   None of the above

Q4. Increasing the rpm of the agitator will -
       (A)   Decrease the KLa
       (B)   Increase the KLa
       (C)   Neither increase nor decrease the KLa
       (D)   Instantaneously increase the KLa but eventually decrease.

Q5. Increasing the height of fermentation broth in a bioreactor will -
       (A)   Increase the KLa
       (B)   Decrease the KLa
       (C)   Will have no effect on KLa
       (D)   None of the above

Q6. The dissolved oxygen in the bioreactor can be increased -
       (A)   By increasing the rpm of the agitator
       (B)   By increasing the air flow rate in the sparger
       (C)   By either increasing the rpm or by increasing the air flow rate in the sparger.
       (D)   Any of the above answer is true

Q7. The advantages of the KLa measurement by dynamic method are -
       (A)   It can be performed under actual fermentation conditions
       (B)   It does not require expensive probes
       (C)   It does not affect the culture behavior in the bioreactor
       (D)   None of the above

Q8. The disadvantages of the KLa measurement by dynamic method are -
       (A)   The membrane permeability of the dissolved oxygen probe may get affected by increase in vessel pressure during the cultivation.
       (B)   The growing cells may get deposited on the Dissolved Oxygen probe and thereby change the probe characteristics.
       (C)   The “air on” and “air off” may lead to shock to the growing culture and result in development of instantaneous mutants thereby altering the production formation capabilities
       (D)   All of the above

Q9. The magnitude of KLa is -
       (A)   Dependent on the vessel geometry alone
       (B)   Dependent on both vessel geometry and air flow rate
       (C)   Dependent only on respiring activity of the culture in the bioreactor
       (D)   Both (A) and (B) are true

Q10. The dissolved oxygen in the fermentation broth can be increased by -
       (A)   Purging air with increased percentage of oxygen in the air
       (B)   By increasing agitation of the bioreactor
       (C)   By manipulating the distance between sparger and the agitator
       (D)   Any of the above methods.