Match the Variation of Reaction Spontaneity (Sign of ΔG) given in Column I with the Signs of ΔH and ΔS given in column II.

COLUMN I	COLUMN II
	ΔH	ΔS	ΔG = ΔH – TΔS
1.	−	+	a. The reaction is both enthalpically and entropically opposed. It is nonspontaneous (endergonic) at all temperatures.
2.	−	−	b. The reaction is enthalpically opposed (endothermic) but entropically favored. It is spontaneous only at temperatures above T = ΔH/ΔS.
3.	+	+	c. The reaction is enthalpically favored but entropically opposed. It is spontaneous only at temperatures below T = ΔH/ΔS.
4.	+	−	d. The reaction is both enthalpically favored (exothermic) and entropically favored. It is spontaneous (exergonic) at all temperatures.

#Question id: 14306

#SCPH05 I Biotechnology

Pseudomonas putida with mm = 0.5 h^-1 is cultivated in a continuous culture under aerobic conditions where D = 0.28 h^-1 . The carbon and energy source in the feed is lactose with aconcentration of S₀ = 2 g/l. The effluent lactose concentration is desired to be S = 0.1 g/l. If the growth rate is limited by oxygen transfer, by using the following information:

Determine the steady-state biomass concentration (X)

                _________________

#Question id: 14308

#SCPH05 I Biotechnology

Pseudomonas putida with µm = 0.5 h^-1 is cultivated in a continuous culture under aerobic conditions where D = 0.28 h^-1 . The carbon and energy source in the feed is lactose with aconcentration of S₀ = 2 g/l. The effluent lactose concentration is desired to be S = 0.1 g/l. If the growth rate is limited by oxygen transfer, by using the following information:

What should be the oxygen-transfer coefficient (k_La) in order to overcome oxygentransfer limitation (i.e., CL = 2 mg/l)? ___________________

#Question id: 14309

#SCPH05 I Biotechnology

Glucose is converted to ethanol by immobilized yeast cells entrapped in gel beads. The specific rate of ethanol production is: q_P = 0.2 g ethanol/g-cell-h. The effectiveness factor for an average bead is 0.8. Each bead contains 50 g/L of cells. The voids volume in the column is 40%. Assume growth is negligible (all glucose is converted into ethanol). The feed flow rate is F = 400 l/h and glucose concentration in the feed is S_0i = 150 g glucose/l. The diameter of the column is 1 m and the yield coefficient is about 0.49 g ethanol/g glucose. The column height is 4 m. What is the glucose conversion at the exit of the column?

#Question id: 14310

#SCPH05 I Biotechnology

Glucose is converted to ethanol by immobilized yeast cells entrapped in gel beads. The specific rate of ethanol production is: q_P = 0.2 g ethanol/g-cell-h. The effectiveness factor for an average bead is 0.8. Each bead contains 50 g/L of cells. The voids volume in the column is 40%. Assume growth is negligible (all glucose is converted into ethanol). The feed flow rate is F = 400 l/h and glucose concentration in the feed is S_0i = 150 g glucose/l. The diameter of the column is 1 m and the yield coefficient is about 0.49 g ethanol/g glucose. The column height is 4 m. What is the ethanol concentration in the exit stream?

#Question id: 14311

#SCPH05 I Biotechnology

Consider following fig, which applies to a fed-batch system.

Assume at t = 0, V = 100 l, X = 2 g/l, m = 1 h-1 , S0 = 4 g/l, and S = 0.01 g/l. V is increased at a constant rate such that dV/dt = 20 l/h = F (or flow rate) and X is constant at all times. What is µ at t = 5 h?

#Question id: 14312

#SCPH05 I Biotechnology

An industrial waste-water stream is fed to a stirred-tank reactor continuously and the cells are recycled back to the reactor from the bottom of the sedimentation tank placed after the reactor. The following are given for the system: F = 100 l/h; S0 = 5000 mg/l; mm = 0.25 h-1 ; Ks = 200 mg/l; α (recycle ratio) = 0.6; C (cell concentration factor) = 2; Y ^M _X/S = 0.4. The effluent concentration is desired to be 100 mg/l.  Determine the required reactor volume.