Fermentation Reactors

Question: A continuous reactor at steady state contains 0.04 g.l-1 of biomass and 0.02 g.l-1 of phenol. The feed contained 0.1 g.l-1 of phenol. The biomass yield would be
[A].

0.4 g.g-1

[B].

0.5 g.g-1

[C].

1.0 g.g-1

[D].

5.0 g.g-1

Answer: Option B

Explanation:

No answer description available for this question.

Question: On a glucose medium, the growth of an organism is characterized by the following Monod model and stoichiometric parameters μm = 0.3 h-1, Ks =0.05 g.l-1 and Yxs = 0.3 g.g-1 When this organism is grown in a 2 litre continuous on a medium containing 10 g.l-1 of glucose added at 1 l.h-1, the steady state concentration of biomass in the reactor will be
[A].

0 g.l-1

[B].

0.4 g.l-1

[C].

0.5 g.l-1

[D].

10 g.l-1

Answer: Option A

Explanation:

No answer description available for this question.

Question: 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

Answer: Option B

Explanation:

No answer description available for this question.

Question: Pseudo-steady state in a continuous reactor refers to a reactor in which
[A].

Pseudomonads are being cultured

[B].

concentration oscillate around a mean value

[C].

concentration increase with time

[D].

concentration decrease with time

Answer: Option B

Explanation:

No answer description available for this question.

Question: Which of the statement is true for continuous reactor at steady state?
[A].

The rates of biomass, substrate and product concentrations are zero

[B].

Biomass, substrate and product concentrations are zero

[C].

Biomass, substrate and product concentrations do not change with time

[D].

Biomass, substrate and product concentrations change with time

Answer: Option C

Explanation:

No answer description available for this question.

Question: In batch culture, protogon is produced from peptone during the stationary phase with a yield of 0.4 protogon mg per g of peptone. If it is to be produced in a chemostat at a dilution rate of 0.5 h-1 from a medium containing 10 g.l-1 of peptone, then the rate of protogon synthesis would be
[A].

0 g.l-1h-1

[B].

0.5 g.l-1h-1

[C].

1 g.l-1h-1

[D].

2 g.l-1h-1

Answer: Option A

Explanation:

No answer description available for this question.

Question: Which of the following is not correct with regards to continuous cultures?
[A].

The major industrial scale application of continuous cultures is in waste water treatment

[B].

Mutation and contamination present a major risk to the operation of continuous cultures for the production of metabolites

[C].

The continuous cultures is very useful for the production of pharmaceuticals

[D].

Continuous cultures have an advantage that they do not need to shut down as regularly as batch culture reactor

Answer: Option C

Explanation:

No answer description available for this question.

Question: Pseudomonas aeruginosa has a maximum specific growth rate of 0.8 h-1 in a medium with glucose as a growth limiting substrate. To prevent wash out, the dilution rate must be set to
[A].

greater than 0.8 h-1

[B].

less than 0.8 h-1

[C].

equal to 0.8 h-1

[D].

1.6 h-1

Answer: Option B

Explanation:

No answer description available for this question.

Question: In a glucose-yeast extract medium, Lactococcus lactis has a maximum specific growth rate (um) of 1.23 h-1. What would be the specific growth rate of this organism at steady state in a 4 litre reactor being fed at 2 litres per hour?
[A].

0.5 h-1

[B].

1.2 h-1

[C].

2.4 h-1

[D].

4 h-1

Answer: Option A

Explanation:

No answer description available for this question.

Question: When two populations compete for a single growth limiting substrate in a continuous fermenter, which organism would not be washed out?
[A].

Organism maintaining the highest substrate concentration

[B].

Organism maintaining the lowest substrate concentration

[C].

Both (a) and (b)

[D].

Organism maintaining the moderate substrate concentration

Answer: Option B

Explanation:

No answer description available for this question.