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Home Biochemical Engineering Fermentation Reactors Comments

  • Question
  • In a fluidized bed reactor mixing is achieved by


  • Options
  • A. gravity flow of fluid
  • B. upward movement of the incoming feed
  • C. diffusion
  • D. both (a) and (b)

  • Correct Answer
  • both (a) and (b) 


  • Fermentation Reactors problems


    Search Results


    • 1. Saccharomyces cerevisiae when grown in high glucose concentration medium, the cells activity depends on which of the following?

    • Options
    • A. High concentration of dissolved oxygen
    • B. Low concentration of dissolved oxygen
    • C. No effect of dissolved oxygen
    • D. High concentration of dissolved oxygen and sodium salts
    • Discuss
    • 2. The production of an amylase from starch by Aspergillus niger is often performed in a fed batch fermenter. This is due to the reason that

    • Options
    • A. fed-batch reactor can be used to minimize starch concentrations and prevent a. niger from fermenting
    • B. fed-batch reactor can be used to minimize starch concentrations and thus reduce the viscosity of the medium
    • C. continuous reactor can be used to minimize starch concentrations and their inhibitory effects
    • D. all of the above
    • Discuss
    • 3. In a batch reactor specific growth rate

    • Options
    • A. remains constant throughout the process
    • B. increases exponentially
    • C. changes during the fermentation
    • D. is highest during the stationary phase
    • Discuss
    • 4. The specific growth rate is affected by

    • Options
    • A. sabstrate concentration
    • B. product concentration
    • C. oxygen supply
    • D. all of these
    • Discuss
    • 5. The bubble column fermenter is usually limited to

    • Options
    • A. aerobic fermentations
    • B. anaerobic fermentations
    • C. Both (a) and (b)
    • D. facultative fermentation
    • Discuss
    • 6. A fed-batch reactor containing 2 litre of medium and 0.1 g.l-l of biomass is fed with a medium containing 1 g.l-1 of substrate at 1 litre per hour. If after 10 hours, the concentration of biomass in the reactor was 0.2 g.l-1, then the biomass produced during the 10 hour period is

    • Options
    • A. 1.5 g
    • B. 2.2 g
    • C. 3.0 g
    • D. 6.0 g
    • Discuss
    • 7. A strain of Escherichia coli has a maximum specific growth rate of 0.8 h-1 on a glucose based medium. If this organism is being grown in a chemostat with a dilution rate of 1.2 h-1, then at steady state the concentration of E. coli in the same medium will

    • Options
    • A. increase
    • B. be zero
    • C. change randomly
    • D. decrease
    • Discuss
    • 8. Which of the following is best described as secondary metabolite?

    • Options
    • A. Acetic acid produced from the oxidation of ethanol
    • B. Ethanol from the fermentation of glucose
    • C. Penicillin
    • D. Citric acid from the partial oxidation of glucose
    • Discuss
    • 9. When the product formation is approximately equal to the rate of cell growth, the pattern of product formation is termed as

    • Options
    • A. uncoupled
    • B. growth associated
    • C. non-growth associated
    • D. metabolically uncoupled
    • Discuss
    • 10. Which of the following would be correct concerning the concentration of biomass (X). growth limiting substrate (S) and product (P) in a chemostat when the cells have been washed out?

    • Options
    • A. X,S and P will be zero
    • B. X,S and P can not be predicted for the above condition
    • C. X and P will be zero while S is equal to the substrate concentration in feed
    • D. None of the above
    • Discuss


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