200 Best MCQs on Fermentation Reactors- biochemical engineering

Q33). A fed-batch reactor initially contains 2 litre of medium. If it was fed at 1 litre per hour, then after 10 hours, the volume of the reactor will be

a).1 litre
b).2 litre
c).3 litre
d).13 litre

Correct Answer:
2 litre
Explaination:

Q34). A Bacillus sp. produces an antibiotic only during the stationary phase when grown in a batch culture. If grown in a 5 litre continuous culture, the steady state productivity of the antibiotic

a).will increase until the culture washes out
b).will decrease after washout
c).will be zero
d).will be infinite

Correct Answer:
will be zero
Explaination:

Q35). In a fluidized bed reactor, the function of the disengagement zone is to

a).reduce loss of particles from the reactor
b).reduce the velocity of the particles near the surface of the reactor
c).reduce foaming problems
d).all of the above

Correct Answer:
all of the above
Explaination:

Q36). 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

Correct Answer:
Fed batch fermenter
Explaination:

Q37). 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

Correct Answer:
0.5 h^-1
Explaination:

Q38). 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

Correct Answer:
The continuous cultures is very useful for the production of pharmaceuticals
Explaination:

Q39). In a plug flow reactor, the highest concentration of substrates is exposed to the cells that

a).are near the effluent or exit of the reactor
b).are in the mid way along the reactor
c).are located near entrance of feed
d).are near the wall of the reactor

Correct Answer:
are located near entrance of feed
Explaination:

Q40). In an activated sludge process, the biomass is recycled to

a).increase the efficiency of the process
b).reduce sludge volumes
c).increase the concentration of cells
d).all of the above

Correct Answer:
all of the above
Explaination: