Match List I with List II
LIST I (Precursor)                                                              LIST II (Fermentation product)
A. Phenylacetic-acid related compounds                     I. Penicillin G
B. Phenoxy acetic acid                                                     II. Penicillin V
C. Cyanides                                                                        III. Vitamin B 12
D. L-Threonine                                                                  IV. Cyclosporin C

Choose the correct answer from the options given below:
1. A- II, B-I, C-IV, D-III
2. A-I, B-II, C-III, D- IV
3. A- IV. B-II, C-III, D-I
4. A- II, B-III, C-IV, D-I

Matching Precursors with Fermentation Products

Fermentation processes utilize specific precursors to produce valuable biochemical compounds, including antibiotics and vitamins. The correct pairing of precursors with their respective fermentation products is essential for optimizing industrial bioproduction.

Correct Answer: Option 2 (A-I, B-II, C-III, D-IV)

Let’s analyze the correct matches:

List I (Precursor) → List II (Fermentation Product)

A. Phenylacetic Acid Related Compounds → I. Penicillin G

• Phenylacetic acid is a precursor in the biosynthesis of Penicillin G (benzylpenicillin), an important β-lactam antibiotic.
• This antibiotic is effective against Gram-positive bacteria.

B. Phenoxyacetic Acid → II. Penicillin V

• Phenoxyacetic acid is used as a precursor in the production of Penicillin V (phenoxymethylpenicillin).
• It is an orally stable form of penicillin used for treating bacterial infections.

C. Cyanides → III. Vitamin B12

• Cyanide derivatives play a key role in the biosynthesis of Vitamin B12 (cobalamin).
• The vitamin is essential for DNA synthesis and red blood cell production.

D. L-Threonine → IV. Cyclosporin C

• L-Threonine is involved in the production of Cyclosporin C, an immunosuppressant used in organ transplantation.
• It is a cyclic peptide that inhibits T-cell activation.

Understanding the Role of Precursors in Fermentation

Each precursor serves a specific function in microbial biosynthesis, influencing yield and efficiency:

1. Role of Precursors in Antibiotic Production

• Precursors like phenylacetic acid and phenoxyacetic acid are incorporated into the penicillin nucleus during Penicillium chrysogenum fermentation.

2. Vitamin B12 Biosynthesis

• Cyanide ions form cyanocobalamin, the stable form of Vitamin B12.
• Fermentation using Propionibacterium and Pseudomonas species enhances B12 production.

3. Cyclosporin Production and Its Importance

• L-Threonine acts as a precursor for cyclosporin biosynthesis in Tolypocladium inflatum.
• Cyclosporins are critical for preventing organ transplant rejection.

Applications of Fermentation-Derived Products

• Antibiotics: Treatment of bacterial infections.
• Vitamins: Essential for human health and metabolic processes.
• Immunosuppressants: Used in autoimmune disease management and organ transplants.

Conclusion

The correct precursor-product match is A-I, B-II, C-III, D-IV (Option 2). Understanding these biochemical pathways is crucial in biotechnology and industrial fermentation, ensuring efficient production of antibiotics, vitamins, and pharmaceuticals.