1. Which of the following is a type of Fed-Batch culture?
a) Variable volume
b) External Feedback
c) Internal Feedback
d) Chemostat
Explanation: There are two types of Fed-Batch culture: Variable-volume fed-batch culture and fixed-volume fed-batch culture. The external feedback, internal feedback, chemostat are the types of continuous fermentation
2. Which scientist(s) described the kinetics of variable-volume fed-batch culture?
a) Dunn and Mor
b) Maniatis et al.
c) Van’t Hoff
d) Maxwell
Explanation: The kinetics of variable-volume fed-batch culture have been developed by Dunn and Mor in 1975 and Pirt in 1974, 1975, 1979.
3. What happens in a Quasi-Steady state?
a) Specific growth increases
b) Specific growth decreases
c) Specific growth becomes constant
d) Specific growth becomes zero
Explanation: In a Quasi-steady state, specific growth gradually decreases. It is a state where all the variables become constant. The Quasi-state approximation is useful in studying the kinetics of certain chemical reactions.
4. What is the condition for a Quasi-Steady state?
a) µ = 0
b) µ = D
c) D = F
d) µ = F
Explanation: Although the total biomass in the culture increases with time, cell concentration(x) remains virtually constant, that is (dx/dt) = 0 and therefore µ = D (approx.). This situation is termed as a Quasi-Steady State.
5. In Variable-volume fed-batch culture, the broth volume remains almost the constant.
a) true
b) false
Explanation: In Variable-volume fed-batch culture, volume changes with fermentation time due to the substrate feed. That is why the name is variable-volume fed-batch culture. Whereas, in fixed-volume fed-batch culture, volume remains the same.
6. Which of the following does not include in the range of fermentation processes?
a) Microbial Enzymes
b) Microbial metabolites
c) Biotransformation
d) Recombinant DNA
Explanation: The range of fermentation processes includes microbial enzymes, microbial metabolites, biotransformation, recombinant protein, microbial cells. Recombinant DNA is produced by rDNA technology
7. Which of the following was used in the production of bakers’ yeast?
a) Batch culture
b) Continuous culture
c) Fed-Batch culture
d) Solid state culture
Explanation: Fed-Batch culture was used in the production of bakers’ yeast as early as 1915. Bakers’ yeast is a yeast useful in the production of a variety of bread in the baking industry. Saccharomyces cerevisiae is known as Bakers’ yeast, is useful for the production of yeast and alcohol.
8. Which of the following is correct with respect to Fermentation?
a) A process involving the mass culture of micro-organisms
b) It is a fast process
c) Fermented food products are always healthy
d) Oxygen is produced during fermentation
Explanation: Fermentation is a slow process involving the mass culture of micro-organisms, production of alcoholic beverages, food spoilage, growth dependent on substrate-level phosphorylation. Sometimes it can lead it gastric cancer.
9. In fixed-volume fed-batch culture, volume changes with fermentation time due to the substrate feed.
a) true
b) false
Explanation: In fixed-volume fed-batch culture, the broth volume remains almost the constant. Hence, the name is fixed-volume. Whereas, in variable-volume fed-batch culture, the volume keeps on changing.
10. Who developed a method for the optimization of the fed-batch system?
a) Shioya
b) Queener
c) Swartz
d) Waki
Explanation: Shioya in 1990 developed a method for the optimization of fed-batch culture based on the relationship of µ and qp.