GATE HELPLINE ANSWER KEY FOR BIOPROCESS MCQs-I
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Transcript of GATE HELPLINE ANSWER KEY FOR BIOPROCESS MCQs-I
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1. Diauxic patter of the biomass growth is associated with
P) Multiple lag phases
Q) Sequential utilization of multiple substrates
R) Simultaneous utilization of multiple substrates
S) Absence of lag phase
a) P,R c) R,S
b) P,Q d) Q,S
2. Match the following
P) Sedimentation coefficient 1. Aqueous two-phase extraction
Q) Partition coefficient 2. Ultracentrifugation
R) Rejection coefficient 3. Dialysis
S) Activity coefficient 4. Centrifugation
a) P-3, Q-1, R-4, S-2 c) P-2, Q-1, R-4, S-3
b) P- 4, Q-3, R-1, S-2 d) P-4, Q-1, R-2, S-3
3. Match the following
A) Marine type impeller 1. Recirculation of medium
B) Draft tube 2. Aeration of medium
C) Diaphragm valve 3. Animal cell cultivation
D) Sparger 4. Sterile operation
a) A-4, B-2, C-1, D-3 c) A-3, B-1, C-4, D-2
b) A-3, B-4, C-2, D-1 d) A-2, B-1, C-4, D-3
4. In a chemostat, evaluation the dilution rate at the cell wash out condition by applying monod’s
model with the given set of data µmax = 1 h-1
; YX/S = 0.5gg-1
; Ks = 0.2 gL-1
; S0 = 10g L-1
a) 1.00 h-1
c) 0.98 h-1
b) 0.49 h-1
d) 1.02 h-1
By the given data:
µmax = 1 h-1
maximum growth rate
Ks = 0.2 gL-1
monods constant
S0 = 10g L-1
initial substrate concentration
The dilution rate at wash out condition is Dcrit=?
Dcrit= µmax S0/ (Ks+ S0)
Substituting the values in equation
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We get 0.98 hr-1
5. A bacterial culture with an approximate biomass composition of CH1.8O0.5N0.2 is grown
aerobically on a defined medium containing glucose as the sole carbon source and ammonia
being the nitrogen source. In this fermentation, biomass is formed with a yield coefficient of
0.35 gram dry cell weight per gram of glucose and acetate is produced with a yield coefficient of
0.1 gram acetate per gram of glucose. The respiratory coefficient for the above culture will be
a) 0.90 c)1.00
b) 0.95 d)1.05
6. A bacterial culture having a specific oxygen uptake rate of 5 mmol O2 (g-DCW)-1
hr -1
is being
grown aerobically in a fed- batch bioreactor. The maximum value of the volumetric oxygen
transfer coefficient is 0.18s-1
for the stirred tank bioreactor and the critical dissolved oxygen
concentration is 20% of the saturation concentration (8 mg/ml). the maximum density to which
the cells can be grown in the fed-batch process without the growth being limited by oxygen
transfer is approximately
a) 14 g/l c) 32 g/l
b) 26 g/l d) 65 g/l
A double reciprocal plot was created from the specific growth rate and limiting substrate
concentration data obtained from a chemostat experiment. A linear regression gave of 1.25 hr and
100 mg-hr-1
for the intercept and slope, respectively.
7. The respective values of the Monod kinetic constants µm (hr-1
) and Ks (mg/l) are as follows:
a) 0.08,8 c) 0.8,80
b) 0.8,0.8 d) 8,8
Solution:
Intercept = 1.25 hr
Slope = 100 mg hr l-1
Now we have to find the maximum growth rate and Monod’s constant
From the reciprocal plot of Monod’s equation
1/µ= Ks/ µm*1/S+1/ µm
Y=mX+C
C = intercept = 1/ µm => 1.25 = 1/ µm => µm = 0.8
m = slope = Ks/ µm=> 100= Ks/ µm=> 100*0.8=Ks => Ks = 80
8. The same culture (with the µm and Ks values as computed above) is cultivated in a 10-litre
chemostat being operated with a 50 ml/min sterile feed containing 50g/l of substrate. Assuming
an overall yield coefficient of 0.3 g-DCW / g- substrate, the respective values of the outlet
biomass and substrate concentrations are
a) 15 g/L, 48 mg/L c) 15g/L, 0.48 g/L
b) 48 g/L,15 g/L d) 4.8 g/L, 4.8 g/L
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Solution:
Given data is some for above problem & hence
µm = 0.8 hr-1
Ks = 80 mg/l
Total volume (V) = 10 lit
Flow rate (F)= 50 ml/ min
S0 = 50g/ lit
Yield Y = 0.3 g-DCW/ g-substrate
To find: biomass X and limiting substrate concentration
Monod equation
S = Ks D/ µm -D
D= F/V
F= 50 ml/ min = 3000ml/ hr
D= F/V = 3000/10000 = 0.3
S= 80*0.3/0.8-0.3 = 48 mg/l
X = y [So - S]
X = 0.3 *[50-0.048] = 0.3 [49.952] = 14.985 = 15 g/l
9. The respiratory coefficient for the reaction
aCHmOn + b O2 + cNH3 d CHαOβNγ + eH2O+ fCO2 is defined as
a) f/a c) b/f
b) e/b d) f/b
10. match the following
A. Pressure 1. photometer
B. Foam 2. rotameter
C. Turbidity 3. diaphragm gauge
D. Flow rate 4. rubber sheathed electrode
a) A-3 B-4 C-1 D-2 c) A-1 B-3 C-2 D-4
b) A-4 B-1 C-2 D-3 d) A-1 B-2 C-3 D-4