# DBT JRF 2020 — Question 116

Exam: DBT JRF 2020 · Section: B · Topic: Biotechnology · Difficulty: Hard

## Question

Which of the following is NOT used for producing vitamins industrially?

## Options

- **A.** Propionibacterium freudenreichii
- **B.** Corynebacterium sp.
- **C.** Pseudomonas aeruginosa
- **D.** Ashbya gossypii

## Answer

Option C

## Explanation

Industrial vitamin microbial producers: Vitamin B2 (Riboflavin): Ashbya gossypii (Eremothecium ashbyi) — natural overproducer; also engineered Bacillus subtilis. Vitamin B12 (Cobalamin): Propionibacterium freudenreichii and Pseudomonas denitrificans. Various vitamins/amino acids: Corynebacterium glutamicum — primarily used for glutamate and lysine, but also some B vitamins. Pseudomonas aeruginosa is an OPPORTUNISTIC HUMAN PATHOGEN (causes nosocomial pneumonia, wounds, UTI in immunocompromised patients). It is NOT used in industrial fermentation for food/pharmaceutical-grade vitamin production due to its pathogenicity and ability to produce virulence factors. Its use would violate regulatory safety standards (GRAS status required for food-grade organisms).

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