Which of the following statements is always correct about an ideal chemostat?
P. Substrate concentration inside the chemostat is equal to that in the exit stream.
Q. Optimal dilution rate is lower than critical dilution rate.
R. Biomass concentration increases with increase in dilution rate.
S. Cell recirculation facilitates operation beyond critical dilution rate.

Which of the following techniques is best suited for immobilizing an affinity ligand?

Which one of the following can not be a limiting substrate if Monod's growth kinetics is applicable?

During cultivation of microorganisms in a fermenter, various parameters are controlled by appropriate sensor (probe). Match each probe in Group I with the appropriate response mechanism in Group II.

Group I (Probe)	Group II (Response)
P. Thermistor	1. Activation of acid/alkali pump
Q. Oxygen electrode	2. Activation of vegetable oil pump
R. Metal rod	3. Activation of hot/cold water pump
S. pH electrode	4. Increase/decrease in stirrer motor speed

The kinetics of the disintegration of baker's yeast cells in a bead mill is described as $$\frac{{dp}}{{dt}} = K\left( {{P_m} - P} \right)$$   , where P is the concentration of protein released, m is the maximum protein concentration achievable, K is the first order rate constant and is 0.5 h⁻¹ for the system studied. The time required for the release of 90% of the intracellular proteins will be: