8. In koji process for the fermentation to produce citric acid,
A.A. niger is used with solid substrate as sweet potato
B.A. niger floats on the surface of solution
C.Fungal mycelium grows through out the solution in a deep tank
D.both (a) and (b)

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9. What is the pH of the medium when molasses is used as substrate for the production of citric acid?
A.3
B.4
C.5
D.6

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10. Which of the following nitrogen sources is added in the fermentation medium of citric acid production?
A.Ammonium salt
B.Urea
C.Both (a) and (b)
D.Peptone

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11. In submerged process for the fermentation to produce citric acid,
A.A. niger is used with solid substrate as sweet potato
B.A. niger floats on the surface of solution
C.Fungal mycelium grows through out the solution in a deep tank
D.both (a) and (b)

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12. Which substrate is used in the fermentation of citric acid?
A.Beet molasses
B.Sucrose
C.Starch hydrolysate
D.All of these

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13. Alegar is a type of vinegar produced from
A.fruit juices
B.malted grain
C.ethanol
D.ale

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14. During recovery step of citric acid, calcium citrate formed is treated with which of the following acid to precipitate calcium?
A.HCl
B.HNO3
C.H2SO4
D.None of these

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