Biochem - Fermentation Kinetics [1]

Question 1

1. The function of the disengagement zone in an airlift fermenter is to

Answer 1

1. Prevent CO2 rich bubbles from entering the downcomer

Question 2

2. Stationary phase is described as

Answer 2

2. No further increase in the cell population after a maximum value

Question 3

3. In the accelerated phase, cell starts to

Answer 3

3. Increase and the division rate increases to reach a maximum

Question 4

4. The Monod model predicts that the specific growth rate

Answer 4

4. Will increase with the concentration of the growth limiting substrate until it reaches a maximum value

Question 5

5. A mixed fermentation is one, which produces

Answer 5

5. Both acid and alcohol

Question 6

6. The function of a mechanical seal is to

Answer 6

6. Prevent contaminants entering the reactor

Question 7

7. The phenomenon in which substrates are used in a sequential manner is known as

Answer 7

7. Diauxie

Question 8

8. The dilution rate, D is defined as

Answer 8

8. F/VR

Question 9

9. Diauxie is

Answer 9

9. The stagewise uptake of nutrients

Question 10

10. An open system in which the growth rate is maintained by adding a nutrient (present in limiting quantities) at the same rate as that medium containing micro-organism is removed is called

Answer 10

10. Chemostat

Question 11

11. In the death phase

Answer 11

11. Nutrients available for the cells are depleted and begin to die

Question 12

12. The maximum specific growth rate of an organism depends on

Answer 12

12. All of these

Question 13

13. Which of the following is not correct for the Monod model and the Michaelis Menten Model

Answer 13

13. The Michaelis Menten Model was derived from a curve fitting exercise

Question 14

14. Bubble column reactor has

Answer 14

14. Large height to diameter ratio

Question 15

15. Why a T-flask used in small-scale cell culture is incubated in a horizontal position

Answer 15

15. To increase the surface area of the liquid-air interface

Question 16

16. An open system in which the growth rate is maintained by the removal and addition of media at such a rate as to maintain a constant cell density is called

Answer 16

16. Turbidostat

Question 17

17. Wash out in steady state fermentation occurs when

Answer 17

17. Dilution rate is higher than the maximum specific growth rate

Question 18

18. Fermenter should be filled with medium upto

Answer 18

18. 75-80%

Question 19

19. Bacterial growth curve is obtained by plotting

Answer 19

19. Log of number of cells versus time

Question 20

20. When intracellular enzymes of whole cells are to be used in a bio-conversion process, it is often necessary to ______ the cells.

Answer 20

20. Permeabilize

Question 21

21. Heat transfer rates (per unit volume) will be lowest in

Answer 21

21. Continuous packed bed reactor

Question 22

22. The function(s) of the draft tube in an airlift bioreactor is

Answer 22

22. To reduce bubble coalescence

Question 23

23. The Monod Model relates

Answer 23

23. Specific growth rate to the substrate availability

Question 24

24. The height to diameter ratio (H/D) for the column fermenters is

Answer 24

24. 3

Question 25

25. The high oxygen transfer efficiencies of airlift bioreactors is due to

Answer 25

25. The draft tube, which reduces bubble coalescence in the reactor

Question 26

26. The maximum specific growth rate (μm) of an organism in batch culture is equal to slope of a plot of

Answer 26

26. In [biomass] against time

Question 27

27. The region of an airlift bioreactor in which the liquid travels in a downward direction is called the

Answer 27

27. Downcomer

Question 28

28. Population doubling time, td can be expressed as

Answer 28

28. ln2/μ

Question 29

29. A higher Ks value of Monod's equation means

Answer 29

29. Lower affinities to substrate

Question 30

30. The increased air flow rate in bubble column fermenter can cause excessive foaming and high retention of air bubbles in the column which

Answer 30

30. Decreases the productivity of the fermenter

Question 31

31. Which of the following is correct for the prediction of time requirement in a batch fermenter?

Answer 31

31. Both (a) and (b)

Question 32

32. In an airlift bioreactor, the spent gases released from the liquid are called

Answer 32

32. Flotsam

Question 33

33. The contents in jet loop reactor are mixed through

Answer 33

33. External pumping

Question 34

34. The specific growth rate (μ) is defined as

Answer 34

34. The rate of individual cells division or increase in their biomass

Question 35

35. The number of baffles in a standard stirred tank bioreactor is

Answer 35

35. 4

Question 36

36. In the stationary phase

Answer 36

36. Growth rate is equal to death rate

Question 37

37. Which of the following is an example of a mathematical model?

Answer 37

37. The Monod Model

Question 38

38. Biomass concentrations during fermentation is

Answer 38

38. All of the above

Question 39

39. Chemostats work on the principle of

Answer 39

39. Maintaining continuous flow of nutrients

Question 40

40. During the exponential phase the maximum specific growth rate equals specific growth rate as

Answer 40

40. Concentration of the growth limiting substrate is much greater than the Monod constant