15. Streptomycin is produced by
A.S. griseus
B.S. griseoflavus
C.S. aerofaciens
D.S. ramosus

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16. Which of the following event occurs during second phase of growth of P. chrysogenum?
A.Synthesis of penicillin is high
B.Synthesis of penicillin is high
C.pH increase
D.Both (a) and (b)

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17.  Inoculum preparation for the fermentation medium for penicillin takes place on
A.wheat seeds
B.barley seeds
C.rice seeds
D.all of these

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18. Antibiotics are typically produced in fed batch reactors because
A.antibiotic yields are generally higher when cells enter the stationary phase
B.the precursors are often toxic to the cells
C.antibiotic yields are generally higher when cell growth slows
D.All of the above

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19. Which of the following event occurs during third phase of growth of P chrysogenum?
A.Concentration of antibiotic increases in the medium
B.Autolysis of the medium starts
C.Slight rise in pH due to liberation of ammonia
D.All of the above

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20. Vegetable oil, (corn oil or soybean oil) added in the fermentation medium for penicillin, act as
A.source of nutrients
B.carbon source
C.antifoam agent
D.both (a) and (c)

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21. Which of the following changes occur during first phase of growth of Penicillium chrysogenum?
A.Growth of mycelia occurs
B.Ammonia is liberated in the medium
C.Lactic acid present in the corn steep liquor is utilized at the maximum rate
D.All of the above

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