16. The specific growth rate is affected by
A. substrate concentration
B. product concentration
C. oxygen supply
D. all of these
17. The main function(s) of a draft tube in an airlift fermenter is/are to
A. increase the solubility of oxygen
B. distribute shear forces throughout the reactor and minimize bubble coalescence
C. concentrate shear forces around the sparger
D. concentrate shear forces near the disengagement zone
18. Which of the following is incorrect?
A. The mechanical agitation and aeration are effective for the suspension of cells
B. The mechanical agitation and aeration are effective for mixing the medium
C. STF can’t be used for high viscosity medium
D. The mechanical agitation and aeration are effective for oxygenation
19. The contents in the bubble column and airlift reactor are mixed through
A. compressed air
B. a mechanical internal moving part
C. external pumping
D. any of these
20. Which of the following statements would be appropriate while comparing bubble column and airlift fermenter of the same size?
A. The average bubble size is smaller in an airlift bioreactor
B. Oxygen transfer rate is higher in an airlift bioreactor
C. The surface area for gas exchange is higher in an airlift bioreactor
D. All of the above