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  • Question
  • 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

  • Correct Answer
  • Penicillin 


  • Fermentation Reactors problems


    Search Results


    • 1. 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
    • 2. 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
    • 3. 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)
    • Discuss
    • 4. 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
    • 5. 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
    • 6. 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
    • 7. 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
    • 8. The fastest route of NADH reoxidation is

    • Options
    • A. aerobic respiration
    • B. anaerobic respiration
    • C. fermentation
    • D. decomposition
    • Discuss
    • 9. The concentration of biomass in a continuous stirred tank reactor is 20 g dry weight per litre. What would be the concentration of biomass in the effluent?

    • Options
    • A. Greater than 20 g dry weight per litre
    • B. Approximately 20 g dry weight per litre
    • C. Lesser than 20 g dry weight per litre
    • D. More than 30 g dry weight per litre
    • Discuss
    • 10. In plug flow tubular reactor the axial velocity profile on cross-section will be

    • Options
    • A. constant
    • B. varying with time
    • C. non-linear
    • D. power function of time
    • Discuss


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