Microbiology Interview Questions and Answers for Experienced people focuses on “World of Bacteria I – Anaerobic Gram-Negative Straight, Curved and Helical Rods”.
1. Bacteria belonging to the family Bacteriodaceae uses which of the following compounds as electron acceptors?
A. oxygen
B. inorganic sulphur
C. nitrate
D. phosphate
Answer: C
Clarification: Bacteriodaceae do not respire anaerobically by using inorganic sulphur as electron acceptors; some do respire anaerobically with nitrate or fumarate.
2. The organic acids produced by bacteria belonging to the family Bacteriadaceae is identified by?
A. distillation
B. gas chromatography
C. spectrophotometer
D. ion-exchange chromatography
Answer: B
Clarification: The bacteria of Bacteriadaceae differ in the kinds of organic acid end products they produce. The organic acids are identified by means of a gas chromatograph.
3. Which of the following genus of bacteria do not have a fermentative type of metabolism?
A. Bacteroides
B. Fusobacterium
C. Wolinella
D. Selenomonas
Answer: C
Clarification: Wolinella do not have a fermentative type of metabolism. They respire anaerobically with hydrogen or formate as electron donors and fumarate or nitrate as electron acceptors.
4. Which of the following possess peritrichous flagella?
A. Bacteroides
B. Anaerovibrio
C. Succinimonas
D. Fusobacterium
Answer: A
Clarification: Bacteroides are straight-rod shaped. They are nonmotile or motile by means of peritrichous flagella.
5. Propionate and acetate are produced as an end product of fermentation in which of the following bacteria?
A. Fusobacterium
B. Succinimonas
C. Wolinella
D. Anaerovibrio
Answer: D
Clarification: Anaerovibrio are slightly curved rod shaped bacteria that are motile by means of a single polar flagellum. They produce propionate and acetate as organic acid end products of the fermentation process.
6. Desulphuromonas can respire with elemental sulphur as the electron acceptor.
A. True
B. False
Answer: A
Clarification: Desuphuromonas is one genus of sulphur reducing bacteria that can respire with elemental sulphur as the electron acceptor. The other genera cannot use sulphur but can use sulphate, thiosulphate, or other oxidized sulphur compounds.
7. Veillonellaceae is the family of bacteria consisting of motile cocci.
A. True
B. False
Answer: B
Clarification: Veillonellaceae consists of nonmotile cocci, typically occurring in pairs, often with the adjacent sides flattened.
8. The violet pigement, violacein, is produced by which of the following bacterial genus?
A. Zymomonas
B. Gardnerella
C. Streptobacillus
D. Chromobacterium
Answer: D
Clarification: Chromobacterium are motile, rod-shaped organisms having the unusual property of forming violet colonies, due to a pigment called violacein. They can cause infections in humans and other mammals.
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