Biochem - Fermentation Kinetics [2] Flashcards
1
Q
- An internal draft tube is preferred to an external draft tube because
A
- Both (a) and (b)
2
Q
- A functional relationship between the specific growth rate and essential compounds concentration was proposed by Monod in
A
- 1942
3
Q
- The optical density sometimes drops during the lag phase because
A
- Cells tend to grow without dividing leading to a decrease in the surface area to volume ratio
4
Q
- The application of just in time (JIT) manufacturing techniques in biotechnology is important because
A
- All of the above
5
Q
- Residence time distribution (RTD) of a reactor is independent of
A
- Micro mixing
6
Q
- The bubble column fermenter is usually limited to
A
- Aerobic fermentations
7
Q
- A culture in a closed vessel to which no additional medium is added and from which no waste products are removed is called a culture.
A
- Batch
8
Q
- If the specific growth rate, μ, is constant with time during the exponential growth period, the equation correlating bacterial number densityCnCn, cell number concentration with respect to time can be expressed as
A
- Cn=Cn0exp[μ(t−t0)]Cn=Cn0exp[μ(t−t0)]
9
Q
- The diameter of the baffles in a standard stirred tank bioreactor ranges from
A
- 1/10th - 1/12th of the tank diameter
10
Q
- During the log phase cell numbers increase exponentially
A
- Because cells are auto catalysts
11
Q
- Lag phase occurs mainly due to
A
- Acclimatization with new environment and substrate
12
Q
- In a batch reactor specific growth rate
A
- Changes during the fermentation
13
Q
- Turbidostat is recommended when continuous fermentation needs to be carried out at
A
- High dilution rates near the washout point
14
Q
- The advantage of airlift bioreactors over stirred tank bioreactors of a similar size is
A
- Both (a) and (b)
15
Q
- Stirred tank fermenter (STF) can be employed for
A
- Both (a) and (b)
16
Q
- The specific growth rate is affected by
A
- All of these
17
Q
- The main function(s) of a draft tube in an air lift fermenter is/are to
A
- Distribute shear forces throughout the reactor and minimize bubble coalescence
18
Q
- Which of the following is incorrect?
A
- STF can’t be used for high viscosity medium
19
Q
- The contents in bubble column and air lift reactor are mixed through
A
- Compressed air
20
Q
- Which of the following statements would be appropriate while comparing bubble column and air lift fermenter of the same size?
A
- All of the above
21
Q
- During the lag phase
A
- Cells synthesize new proteins and membrane components
22
Q
- Concentration of the growth limiting substrate means
A
- The concentration of the substrate that controls the growth rate of the cells
23
Q
- Tower fermenters are used for
A
- Continuous beer production
24
Q
- In wastewater treatment, which bioreactor is generally used?
A
- CSTR
25
Q
- The contents in stirred tank rector are mixed through
A
- A mechanical agitator
26
Q
- The height to diameter ratio (H/D) for the tank fermenters is
A
- <3
27
Q
- The relatively large volume (10 to 40% of total fermenter volume) of the seed culture is employed to
A
- Decrease the overall fermentation time
28
Q
- In an airlift bioreactor, the air sparging region is called
A
- Air riser
29
Q
- The air riser is located on the outside of the draft tube for the large-scale airlift bioreactors because of
A
- Higher oxygen transfer rates
30
Q
- At the end of the lag phase, when growth begins, the division rate increases gradually and reaches a maximum value in the exponential growth period. This transitional period is commonly called the accelerated growth phase and is often included as a part of the
A
- Exponential growth phase
31
Q
- Which of the following(s) is/are considered the limitations of the exponential growth model?
A
- All of the above
32
Q
- To describe components of an airlift bioreactor which of the follow-ings are generally included?
A
- Disengagement zone, air riser, downcomer
