1. Which scientist(s) gave a full kinetic description of external and internal feedback system?
a) Monod
b) Pirt
c) Bull
d) Harte and Webb
Explanation: Pirt in 1975 gave a full description of these feedback systems and he also discussed the kinetics of product of microbial culture.
2. What are the disadvantages of continuous culture?
a) It can rarely be used for other productions
b) The growth rate is higher
c) If contamination occurs, huge volumes of the product may be lost
d) It is very useful for processes involving the production of primary metabolites
Explanation: Continuous culture is an open culture system and therefore, there are very high chances of microbial contamination. Thus, a huge amount of product may be lost. The other three options include the advantages of continuous culture.
3. In continuous culture, the turnover rate is high.
a) true
b) false
Explanation: The turnover rate in continuous culture is higher because the nutrients are added constantly and continuously and thus the products are produced in a high amount.
4. Which of the following is not the type of continuous brewing?
a) Cascade system
b) Multistage system
c) Tower system
d) Extract brewing
Explanation: The main types of continuous brewing are cascade, multisystem and the tower system. The extract brewing is a type of home brewing. The continuous brewing is useful in converting the wort into beer
5. All the constituents of medium are excess in _______
a) Chemostat
b) Turbidostat
c) Batch culture
d) Fed-Batch culture
Explanation: In the continuous culture all the constituents of the medium are in excess in the chemostat. The batch and the fed-batch culture contains a limited amount of nutrients in the medium.
6. Which carbon source has great application for SCP production?
a) Cellulose
b) Starch
c) Methanol
d) Methane
Explanation: Cellulose has been investigated as a potential carbon source for SCP production and was reviewed by Callihan et al and Woodward. Cellulose is a compound present in the cell wall of plants. Humans do not have an enzyme that can digest cellulose, therefore cellulose directly gets excreted in the form of roughage.
7. The continuous culture or fermentation can be used to produce _______
a) Biomass
b) Primary metabolites
c) Secondary metabolites
d) Antibodies
Explanation: The continuous culture or fermentation can be used to produce primary metabolites such as amino acids, SCP, organic acids, etc. Biomass, Secondary metabolites, and a few primary metabolites are produced by batch fermentation.
8. Which of the following is NOT correct for Continuous fermentation?
a) Setup is not changed from outside once the fermentation has started
b) Nutrients are added many times
c) Closer to the natural environment
d) The small size of fermenters are required
Explanation: In Continuous Fermentation the system is open and therefore the setup can be changed from outside during the fermentation process. The other three options are possible for batch fermentation.
9. The Fed-batch culture is a/an ______ culture system.
a) Open
b) Closed
c) Isolated
d) Semi-closed
Explanation: The Fed-batch culture is a closed culture system where the nutrient media is prepared and it is inoculated with culture organism and then is incubated for a particular time. The batch culture is a closed system and continuous culture is an open system.
10. Who introduced the term “Fed-Batch”?
a) Burrow et al.
b) Bu’Lock et al.
c) Yoshida et al.
d) Maniatis et al.
Explanation: The term “Fed-Batch” was introduced by Yoshida et al. to describe the cultures which are fed continuously or sequentially without the removal of culture fluid.