Microbiology Multiple Choice Questions on “Industrial Uses of Molds”.
1. Gluconic acid is produced by which of the following molds?
A. Aspergillus niger
B. Rhizopus nigricans
C. Aspergillus terreus
D. Rhizopus oryzae
Answer: A
Clarification: Aspergillus niger is the producer organism for gluconic acid which is used as a pharmaceutical product, textiles, leather, or in photography.
2. Fermentation of rice is carried out by which of the following microorganisms?
A. bacteria
B. yeasts
C. molds
D. protozoa
Answer: C
Clarification: Molds are used for the fermentation of rice to produce a variety of oriental foods and food additives.
3. Penicillium chrysogenum is a better penicillin producing species.
A. True
B. False
Answer: A
Clarification: Fleming isolated the mold Penicillium notatum which yielded only a few units of penicillin per milliliter. So isloation of a better penicillin-producing mold species, Penicillium chrysogenum helped in increasing the yield.
4. Which of the following techniques is used to improve penicillin production?
A. fed-batch fermentation
B. submerged-culture technique
C. continuous fermentation
D. batch fermentation
Answer: B
Clarification: Penicillin production can be improved by the development of the submerged culture technique i.e., cultivation of the mold in large volumes of liquid medium through which sterile air is forced.
5. Which of the following product acts as a substrate for the production of citric acid?
A. molasses
B. corn-steep liquor
C. barn
D. oyabeen meal
Answer: A
Clarification: Many sugars may serve as the substrate for the production of citric acid, however, molasses is generally used.
6. Which of the following enzymes is used to hydrolyze starch to dextrin?
A. invertase
B. pectinase
C. amylase
D. protease
Answer: C
Clarification: Amylases hydrolyze starch to dextrin and sugars and are used in preparing adhesives, clarifying fruit juices, manufacturing pharmaceuticals etc.
7. Which of the following enzyme is used in the process of bating?
A. invertase
B. pectinase
C. amylase
D. protease
Answer: D
Clarification: Proteases are used for bating i.e. treatment of hides to provide a finer texture and grain in leather processing.
8. Paper, glass beads can be used to immobilize enzymes.
A. True
B. False
Answer: A
Clarification: A variety of substances including paper, wood chips, ceramic, glass beads, and ion-exchange resins have been used to immobilize enzymes.
9. Invertase causes hydrolysis of ___________
A. starch
B. sucrose
C. proteins
D. pectins
Answer: B
Clarification: Invertase hydrolyzes sucrose to form glucose and fructose (invert sugar). It is widely used in candy making and the production of noncrystallizable syrups from sucrose.
10. Rhizopus nigricans produces which of the following products?
A. Citric acid
B. Fumaric acid
C. Gibberellic acid
D. Lactic acid
Answer: B
Clarification: Rhizopus nigricans is used for the production of fumaric acid which is used in the manufacture of alkyd resins and wetting agents.
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