Q.39 The commonly used antibiotic “Erythromycin” is produced by:
1. Bacillus licheniformis
2. Streptomyces erythreus
3. Pencillium chrysogenum
4. Streptomyces antibioticus
Erythromycin Antibiotic Producer: Streptomyces erythreus Identified
Erythromycin, a macrolide antibiotic, is produced by specific soil actinomycetes used in industrial fermentation. The correct answer is option 2: Streptomyces erythreus (now classified as Saccharopolyspora erythraea), a standard fact in microbiology and biotech exams.
Correct Answer
Option 2: Streptomyces erythreus.
This actinomycete, originally isolated from soil, produces erythromycin A via a type I polyketide synthase gene cluster. Industrial strains like NRRL 2338 derive from it, with modern taxonomy recognizing Saccharopolyspora erythraea.
Option Analysis
Option 1: Bacillus licheniformis
Bacillus licheniformis produces enzymes like proteases and amylases for industrial use, but not antibiotics like erythromycin. Known for bacitracin, not macrolides.
Option 2: Streptomyces erythreus (Correct)
The primary producer, yielding erythromycin through fermentation optimized for high titers. Key in treating Gram-positive infections.
Option 3: Penicillium chrysogenum
Fungus producing penicillin, the beta-lactam antibiotic. No erythromycin capability; fungal vs. bacterial metabolism differs.
Option 4: Streptomyces antibioticus
Produces actinomycin D, an antitumor antibiotic, not erythromycin. Different species specialize in distinct secondary metabolites.
| Option | Microorganism | Produces Erythromycin? | Reason |
|---|---|---|---|
| 1 | Bacillus licheniformis | No | Enzyme producer |
| 2 | Streptomyces erythreus | Yes | Macrolide source |
| 3 | Penicillium chrysogenum | No | Penicillin maker |
| 4 | Streptomyces antibioticus | No | Actinomycin D |
Exam Relevance
Questions test antibiotic producers; note taxonomic update to Saccharopolyspora but exam options retain classic name.
