logo

CuriousTab

CuriousTab

Discussion


Home Biochemical Engineering Fermentation Reactors Comments

  • Question
  • Mixing per unit volume is observed to be poorest in


  • Options
  • A. continuous packed bed reactor
  • B. continuous fluidized bed bioreactor
  • C. continuous airlift bioreactor
  • D. none of the above

  • Correct Answer
  • continuous packed bed reactor 


  • Fermentation Reactors problems


    Search Results


    • 1. 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

    • Options
    • A. will increase until the culture washes out
    • B. will decrease after washout
    • C. will be zero
    • D. will be infinite
    • Discuss
    • 2. 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?

    • Options
    • 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
    • Discuss
    • 3. The continuous cultures are not widely used in industry because

    • Options
    • A. they are not suited for the production of secondary metabolites
    • B. contamination or mutation can have a disastrous effect on the operation
    • C. the government will not approve the licensing of pharmaceuticals produced in continuous cultures
    • D. all of the above
    • Discuss
    • 4. Toxins accumulated in a reactor can lead to low biomass yields probably due to which of the following?

    • Options
    • A. NAD+ is diverted away from homeostasis to anabolism
    • B. ATP is diverted away from homeostasis to anabolism
    • C. NAD+ is diverted away from anabolism to homeostasis
    • D. ATP is diverted away from anabolism to homeostasis
    • Discuss
    • 5. Mixing profiles closest to plug flow are observed in

    • Options
    • A. continuous packed bed reactor
    • B. stirred tank reactor with biomass recycles
    • C. continuous fluidized bed bioreactor
    • D. all of these
    • Discuss
    • 6. A continuous reactor has a dilution rate of 0.5 h-1. Its residence time would be

    • Options
    • A. ln(2)/0.5
    • B. ln(2) x 0.5
    • C. 0.5 h
    • D. 2 h
    • Discuss
    • 7. Formation of end product by Lactococcus lactis will become non-growth associated as lactic acid accumulates because

    • Options
    • A. cells will redirect ATP to anabolism
    • B. cells will redirect NAD+ to anabolism
    • C. cells will redirect ATP to facilitate the diffusion of lactic acid and H+ out of the cells
    • D. cells will redirect ATP to the active transport of lactic acid and H+ out of the cells
    • Discuss
    • 8. Yield coefficient represents

    • Options
    • A. total biomass or product produced
    • B. conversion efficiency of a substrate into product
    • C. conversion rate of a substrate into biomass or product
    • D. production time of biomass or product
    • Discuss
    • 9. A continuous bioreactor in which only the flow rate is used to control the rate of cell or product productivity is called

    • Options
    • A. turbidostat
    • B. chemostat
    • C. level stat
    • D. pH
    • Discuss
    • 10. If biomass yields are constant, then the biomass productivity of a culture grown in continuous reactor will

    • Options
    • A. always decrease with dilution rate
    • B. increase with dilution rate until washout
    • C. remain constant irrespective of the dilution rate
    • D. decrease with dilution rate until washout
    • Discuss


    Comments

    There are no comments.

Enter a new Comment