Bioprocessing of glutamic acid MCQs With Answer

Bioprocessing of Glutamic Acid MCQs With Answer is designed for M.Pharm students to build a strong conceptual and practical understanding of microbial glutamate production. This collection focuses on fermentation biology, strain and process engineering, triggers for glutamate secretion, upstream optimization, and downstream recovery and purification. Questions emphasize key operational parameters (pH, temperature, aeration), metabolic and genetic interventions (enzyme targets, cofactor requirements), common bioreactor strategies (fed‑batch, immobilization, scale‑up challenges), and analytical techniques used for quantification and quality control. Use these MCQs to test and strengthen your ability to analyze process decisions, troubleshoot production runs, and prepare for advanced coursework or exam questions in Bioprocess Engineering and Technology.

Q1. Which microorganism is most commonly used for industrial production of L‑glutamic acid (glutamate)?

• Corynebacterium glutamicum
• Escherichia coli
• Bacillus subtilis
• Streptomyces griseus

Correct Answer: Corynebacterium glutamicum

Q2. What is the preferred primary carbon source in commercial glutamate fermentations?

• Glucose
• Lactose
• Glycerol
• Cellobiose

Correct Answer: Glucose

Q3. Which physiological manipulation is classically used to trigger L‑glutamate excretion in C. glutamicum?

• Biotin limitation
• Excess biotin supplementation
• Complete anaerobiosis
• High salt stress

Correct Answer: Biotin limitation

Q4. What is the immediate metabolic precursor for L‑glutamate biosynthesis in the TCA cycle?

• α‑Ketoglutarate (α‑KG)
• Oxaloacetate
• Pyruvate
• Citrate

Correct Answer: α‑Ketoglutarate (α‑KG)

Q5. Which fermentation mode is most often used industrially to maximize glutamate titer and productivity?

• Fed‑batch
• Simple batch
• Continuous chemostat
• Repeated-batch without feed control

Correct Answer: Fed‑batch

Q6. Supplementation of biotin to a glutamate‑producing culture typically causes which effect?

• Suppresses glutamate secretion
• Increases glutamate secretion dramatically
• Has no effect on glutamate production
• Converts glutamate to aspartate

Correct Answer: Suppresses glutamate secretion

Q7. What is the typical optimum incubation temperature for C. glutamicum glutamate production processes?

• Approximately 30°C
• Approximately 37°C
• Approximately 45°C
• Approximately 20°C

Correct Answer: Approximately 30°C

Q8. Addition of surfactants such as Tween or sodium oleate in production medium primarily affects glutamate production by:

• Altering cell membrane permeability and inducing secretion
• Detoxifying glucose medium
• Serving as an alternative carbon source
• Enhancing sporulation

Correct Answer: Altering cell membrane permeability and inducing secretion

Q9. What is the common first downstream unit operation after fermentation to prepare glutamate broth for purification?

• Cell removal by centrifugation or microfiltration
• Ion‑exchange chromatography directly on whole broth
• Direct crystallization from unclarified broth
• Spray drying of whole fermentation slurry

Correct Answer: Cell removal by centrifugation or microfiltration

Q10. Which purification technique is most commonly used to separate and concentrate amino acids like glutamate during downstream processing?

• Ion‑exchange chromatography
• Gel electrophoresis
• Size‑exclusion chromatography
• Solvent extraction with nonpolar solvents

Correct Answer: Ion‑exchange chromatography

Q11. Which by‑product is typically observed in glucose‑based glutamate fermentations and can reduce yield if not controlled?

• Acetate
• Penicillin
• Urea
• Malonate

Correct Answer: Acetate

Q12. Overexpression of which enzyme in C. glutamicum is a common metabolic engineering strategy to increase glutamate synthesis?

• Glutamate dehydrogenase (GDH)
• Lactate dehydrogenase (LDH)
• Citrate synthase
• Alcohol dehydrogenase

Correct Answer: Glutamate dehydrogenase (GDH)

Q13. The industrial fermentation for L‑glutamate production is performed under which oxygen condition?

• Aerobic (high oxygen transfer)
• Strictly anaerobic
• Microaerobic with no agitation
• Facultative with periodic anoxic phases

Correct Answer: Aerobic (high oxygen transfer)

Q14. Treatment with low concentrations of certain beta‑lactam antibiotics (e.g., penicillin) promotes glutamate secretion by:

• Interrupting cell wall synthesis and altering membrane physiology
• Inhibiting glycolysis directly
• Increasing intracellular biotin pools
• Stimulating rRNA synthesis

Correct Answer: Interrupting cell wall synthesis and altering membrane physiology

Q15. For stable growth and glutamate production, pH in the fermenter is typically controlled near which value?

• Near neutral (around pH 7.0)
• Strongly acidic (pH 3.0)
• Highly alkaline (pH 10.0)
• Uncontrolled and allowed to drift

Correct Answer: Near neutral (around pH 7.0)

Q16. Which analytical method is commonly used for accurate quantification of L‑glutamate in fermentation broth?

• HPLC with pre‑column derivatization (e.g., OPA/fluorescence)
• Thin‑layer chromatography with iodine staining
• UV absorbance at 280 nm without derivatization
• Gravimetric analysis after drying

Correct Answer: HPLC with pre‑column derivatization (e.g., OPA/fluorescence)

Q17. What is a major advantage of immobilizing C. glutamicum cells for continuous glutamate production?

• Higher cell density and operational stability enabling prolonged production
• Instant elimination of by‑products without downstream steps
• Complete removal of oxygen requirement
• Guaranteed elimination of contamination without sterilization

Correct Answer: Higher cell density and operational stability enabling prolonged production

Q18. The common bacterial glutamate dehydrogenase used for glutamate biosynthesis prefers which cofactor?

• NADP+ / NADPH
• FAD / FADH2
• Heme iron
• ATP

Correct Answer: NADP+ / NADPH

Q19. Limitation of which cellular biosynthetic process (linked to biotin) leads to membrane alterations and favours glutamate excretion?

• Fatty acid synthesis (lipid metabolism)
• Ribosomal protein synthesis
• Nucleotide biosynthesis
• Peptidoglycan crosslinking exclusively

Correct Answer: Fatty acid synthesis (lipid metabolism)

Q20. During scale‑up from lab to industrial bioreactors, which operational parameter is most frequently the critical challenge affecting glutamate productivity?

• Oxygen transfer (kLa and dissolved oxygen control)
• Light intensity inside the reactor
• Magnetic field strength
• Gravity‑driven mixing without agitation

Correct Answer: Oxygen transfer (kLa and dissolved oxygen control)

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