22. Toxins accumulated in a reactor can lead to low biomass yields probably due to which of the following?
A.NAD+ is diverted away from homeostasis to anabolism
B.ATP is diverted away from homeostasis to anabolism
C.NAD+ is diverted away from anabolism to homeostasis
D.ATP is diverted away from anabolism to homeostasis
23. The cellular productivity in a continuous stirred tank fermenter (CSTF) increases with an increase in the dilution rate and reaches a maximum value. If the dilution rate is increased beyond the maximum point, the productivity will
A.decrease abruptly
B.increase
C.increase drastically
D.be zero
24. Fluidized bed bioreactors provide higher mass transfer rates than packed bed bioreactors because
A.mixing is higher in fluidized bed bioreactors
B.particles move with the fluid in a fluidized bed bioreactor
C.immobilized particles are smaller in the fluidized bed bioreactors
D.all of the above
25. In fed-batch fermentation, mass of substrate utilized is calculated using the relationship
A.initial mass of substrate in the reactor + final mass of substrate in the reactor + flow rate x [substrate in the feed]
B.initial mass of substrate in the reactor - final mass of substrate in the reactor + flow rate x [substrate in the feed]
C.initial mass of substrate in the reactor + final mass of substrate in the reactor - flow rate x [substrate in the feed]
D.initial mass of substrate in the reactor + final mass of substrate in the reactor - flow rate
26. A chemostat has a liquid volume of 2 litres and is being fed at a rate of 4 litres per hour. Dilution rate for this reactor will be
A.2 litres
B.2 litres per hou
C.2 h-1
D.4 litres per hour
27. Mixing per unit volume is observed to be poorest in
A.continuous packed bed reactor
B.continuous fluidized bed bioreactor
C.continuous airlift bioreactor
D.none of the above
28. The growth of an organism on glucose is described by the following Monod model parameters: μm = 0.5 h-1 and Ks =0.1 g.l-1, if the concentration of glucose in the feed is 10 g.l-1 and the dilution rate is set to 0.4 h-1, then the steady state concentration of glucose in the effluent will be
A.0 g.l-1
B.0.5 g.l-1
C.1.0 g.l-1
D.10 g.l-1
Page 4 of 6