Biochemical Engineering

Question: A continuous bioreactor in which only the flow rate is used to control the rate of cell or product productivity is called
[A].

turbidostat

[B].

chemostat

[C].

level stat

[D].

pH

Answer: Option B

Explanation:

No answer description available for this question.

Question: Unsteady state mass balance for dynamic model of continuous stirred tank reactor (CSTR) is
[A].

time rate of total amount in rector = rate of addition to reactor -rate of removal + rate of formation

[B].

total amount in rector = rate of addition to reactor – rate of removal + rate of formation

[C].

rate of total amount in rector = rate of addition to reactor – rate of removal + rate of formation

[D].

none of the above

Answer: Option A

Explanation:

No answer description available for this question.

Question: 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

Answer: Option A

Explanation:

No answer description available for this question.

Question: A culture system with constant environmental conditions maintained through continual provision of nutrient and removal of wastes is called __________ culture system.
[A].

continuous

[B].

batch

[C].

fed-batch

[D].

semi continuous

Answer: Option A

Explanation:

No answer description available for this question.

Question: The continuous cultures are not widely used in industry because
[A].

they are not suited for the production of secondary metabolites

[B].

contamination or mutation can have a disastrous effect on the operation

[C].

the government will not approve the licensing of pharmaceuticals produced in continuous cultures

[D].

all of the above

Answer: Option D

Explanation:

No answer description available for this question.

Question: In a continuous reactor, the medium contains 40 g.l-1 of maltose and the medium flow rate is 10 litres per hour and the effluent contains 20 g.l-l of lactate. What is the productivity of lactate production from this reactor?
[A].

50 g maltose.l-1

[B].

50 g lactate.l-1

[C].

200 g maltose.l-1

[D].

200 g lactate.l-1

Answer: Option D

Explanation:

No answer description available for this question.

Question: Continuous culture has an advantage over to a batch cultures as
[A].

continuous reactors do not need to be shut down and cleaned as regularly as a batch reactor

[B].

most downstream and upstream processes are continuous in nature and thus the operation of continuous bioreactor can be better integrated into the overall manufacturing process

[C].

cells can be maintained at a constant physiological state simply by setting the dilution rate

[D].

all of the above

Answer: Option D

Explanation:

No answer description available for this question.

Question: Saccharomyces cerevisiae produces high biomass yields at low glucose concentrations and high dissolved oxygen concentrations. Which of the following should be followed for maximizing its biomass productivity?
[A].

Batch fermenter with a high initial glucose concentration

[B].

Continuous fermenter with a low initial glucose concentration

[C].

Fed batch fermenter

[D].

All of the above

Answer: Option C

Explanation:

No answer description available for this question.

Question: A fed-batch reactor containing 2 litre of medium and 0.1 g.l-l of biomass is fed with a medium containing 1 g.l-1 of substrate at 1 litre per hour. If after 10 hours, the concentration of biomass in the reactor was 0.2 g.l-1, then the biomass produced during the 10 hour period is
[A].

1.5 g

[B].

2.2 g

[C].

3.0 g

[D].

6.0 g

Answer: Option B

Explanation:

No answer description available for this question.

Question: A fed-batch reactor containing 1 g.l-1 of substrate in 2 litre of medium. It is fed with 1 g.l-l of substrate at the rate of 1 litre per hour. After 10 hours, the concentration of substrate in the reactor was 0.5 g.l-1 . The mass of substrate that was used by the culture in the reactor was
[A].

2g

[B].

6g

[C].

8g

[D].

12g

Answer: Option B

Explanation:

No answer description available for this question.