Bioprocessing of griseofulvin MCQs With Answer

Introduction: Bioprocessing of griseofulvin MCQs With Answer is designed for M.Pharm students specializing in bioprocess engineering and technology. This set provides focused questions that cover upstream and downstream aspects of griseofulvin production, including organism selection, enzymatic biosynthesis (polyketide systems), fermentation strategies (solid-state vs submerged), process parameters (pH, temperature, oxygen transfer), scale-up criteria (kLa, impeller choice), analytical assays (HPLC-UV), and purification techniques. Questions also address strain improvement, in-situ recovery, and quality control considerations relevant to industrial production. These MCQs aim to deepen understanding of practical and theoretical concepts essential for designing and optimizing griseofulvin bioprocesses.

Q1. Which fungal genus is most commonly associated with industrial production of griseofulvin?

• Penicillium
• Aspergillus
• Streptomyces
• Fusarium

Correct Answer: Penicillium

Q2. Griseofulvin biosynthesis in filamentous fungi is primarily routed through which biochemical pathway?

• Polyketide pathway (PKS)
• Shikimate pathway
• Mevalonate (terpenoid) pathway
• Nonribosomal peptide synthetase (NRPS) pathway

Correct Answer: Polyketide pathway (PKS)

Q3. Which type of fungal polyketide synthase is typically responsible for griseofulvin assembly?

• Iterative type I non-reducing PKS
• Modular type I PKS
• Type II PKS (bacterial)
• Type III PKS

Correct Answer: Iterative type I non-reducing PKS

Q4. For higher yields of griseofulvin in lab and pilot studies, which fermentation mode often provides advantages for filamentous producers?

• Solid-state fermentation (SSF)
• Submerged batch fermentation (SmF)
• Chemostat continuous fermentation
• Photo-bioreactor cultivation

Correct Answer: Solid-state fermentation (SSF)

Q5. Which carbon-source strategy commonly favors secondary metabolite production, including griseofulvin, over rapid biomass accumulation?

• Low glucose or complex/carbohydrate polymers (e.g., starch) to avoid catabolite repression
• High initial glucose concentration to maximize growth
• Exclusive use of glycerol as sole carbon source for biomass only
• Constant feeding of high sucrose to maintain exponential growth

Correct Answer: Low glucose or complex/carbohydrate polymers (e.g., starch) to avoid catabolite repression

Q6. What is a typical optimal incubation temperature for many griseofulvin-producing Penicillium strains?

• 25 °C
• 37 °C
• 15 °C
• 45 °C

Correct Answer: 25 °C

Q7. Which initial pH range is generally favorable for griseofulvin production in fungal fermentations?

• Slightly acidic, around pH 5–6
• Strongly alkaline, pH 9–10
• Neutral to slightly alkaline, pH 7.5–8.5
• Extremely acidic, pH 2–3

Correct Answer: Slightly acidic, around pH 5–6

Q8. During scale-up of stirred-tank fermentations for griseofulvin, which scale-up criterion is most useful to maintain oxygen transfer performance?

• Maintaining constant volumetric mass transfer coefficient (kLa)
• Maintaining constant Reynolds number only
• Maintaining identical impeller tip speed across scales
• Maintaining constant working volume percentage only

Correct Answer: Maintaining constant volumetric mass transfer coefficient (kLa)

Q9. Which solvent is commonly used for recovery/extraction of griseofulvin from fungal biomass or fermentation broth?

• Ethyl acetate
• Water
• Acetone–water 50:50
• Glycerol

Correct Answer: Ethyl acetate

Q10. Which analytical technique is the standard choice for routine quantification and purity assessment of griseofulvin in process samples?

• High-performance liquid chromatography with UV detection (HPLC-UV)
• Flame photometry
• Paper chromatography only
• Turbidimetric assay

Correct Answer: High-performance liquid chromatography with UV detection (HPLC-UV)

Q11. At approximately which UV wavelength is griseofulvin typically detected during HPLC-UV analysis?

• ~292 nm
• ~210 nm
• ~550 nm
• ~700 nm

Correct Answer: ~292 nm

Q12. Which downstream purification technique is routinely employed to obtain crystalline griseofulvin after solvent extraction?

• Recrystallization
• Lyophilization without solvent exchange
• Cold water precipitation
• Direct gas-phase chromatography

Correct Answer: Recrystallization

Q13. Which metabolic engineering or strain improvement approach is commonly used to increase griseofulvin titers?

• Random mutagenesis combined with screening and precursor feeding
• Deleting all secondary metabolite clusters indiscriminately
• Replacing fungal PKS with bacterial fatty acid synthase genes
• Eliminating oxygen supply entirely to induce stress

Correct Answer: Random mutagenesis combined with screening and precursor feeding

Q14. The chlorinated moiety in griseofulvin is introduced biosynthetically by which type of enzyme class?

• Halogenase
• Decarboxylase
• Lyase
• Transaminase

Correct Answer: Halogenase

Q15. Which in-situ downstream technique can be applied during fermentation to adsorb and remove griseofulvin, reducing product inhibition and aiding recovery?

• Sorption onto polymeric resins (e.g., Amberlite)
• Direct distillation from broth
• Membrane microfiltration for product removal
• Ultracentrifugation of intact hyphae

Correct Answer: Sorption onto polymeric resins (e.g., Amberlite)

Q16. Which bioreactor configuration is most commonly employed for scale-up of fungal griseofulvin production at industrial scale?

• Stirred-tank reactor (STR)
• Photobioreactor
• Membrane bioreactor without agitation
• Packed-bed reactor with no aeration

Correct Answer: Stirred-tank reactor (STR)

Q17. To minimize shear damage to filamentous fungal morphology during stirred cultivation, which impeller type is often preferred?

• Axial-flow impeller (e.g., pitched-blade)
• High-speed Rushton turbine exclusively
• Multiple small disc turbines at high tip speed
• Static baffles without impellers

Correct Answer: Axial-flow impeller (e.g., pitched-blade)

Q18. Which operational issue commonly arises in fungal griseofulvin fermentations and is typically controlled with antifoam addition or mechanical breakers?

• Excessive foaming
• Excessive electrical conductivity
• Uncontrolled crystallization in broth
• Excessive broth transparency

Correct Answer: Excessive foaming

Q19. Which online process signal is most informative for detecting onset of secondary metabolism and product formation in a griseofulvin fermentation?

• Dissolved oxygen (DO) trend coupled with off-gas CO2
• Conductivity only
• Absolute broth color without spectroscopy
• Manual pellet weight measurement once per day

Correct Answer: Dissolved oxygen (DO) trend coupled with off-gas CO2

Q20. Which quality control concern is critical for griseofulvin produced from fungal cultures before pharmaceutical use?

• Absence of co-produced toxic mycotoxins confirmed by HPLC/LC‑MS
• High residual glucose concentration only
• Presence of live fungal spores in the API
• Retention of fermentation broth color

Correct Answer: Absence of co-produced toxic mycotoxins confirmed by HPLC/LC‑MS

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