Microorganisms in traditional industrial fermentations Which organism below is not traditionally used as the primary microbe in classic industrial fermentations (prior to modern recombinant DNA processes)?
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AEscherichia coli
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BYeast (Saccharomyces spp.)
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CBacillus spp.
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DPseudomonas spp.
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ELactobacillus spp.
Answer
Correct Answer: Escherichia coli
Explanation
Introduction / Context:Classical industrial fermentations focused on organisms that naturally produce large quantities of desired products under controllable conditions. Historically, certain genera dominated due to robustness and yield.
Given Data / Assumptions:
- “Traditional” refers to pre-recombinant, large-scale processes (beer, wine, baking, organic acids, solvents, enzymes, antibiotics).
- Primary production organism is the focus, not contaminants or auxiliary roles.
Concept / Approach:Yeasts (Saccharomyces) are central to ethanol and baking; Bacillus species produce enzymes and antibiotics; Lactobacillus drives lactic fermentations. Escherichia coli became prominent later for recombinant protein production, not as a traditional industrial production microbe. Pseudomonas has niche bioprocesses but was less central historically than Bacillus/yeasts/LAB.
Step-by-Step Solution:
List traditional flagship processes: brewing, winemaking, bread (yeast); lactic acid, yogurt (LAB); enzymes and antibiotics (Bacillus, Streptomyces).Note E. coli’s rise with recombinant DNA in the 1970s–1980s rather than in classic food/commodity fermentations.Select E. coli as not traditionally used as a primary organism.Verification / Alternative check:Industrial history texts emphasize yeasts, LAB, Bacillus, and filamentous fungi long before E. coli entered biopharma.
Why Other Options Are Wrong:
- Yeast/Bacillus/Lactobacillus: foundational in traditional fermentations.
- Pseudomonas: less common but used in some specialty bioprocesses; still more traditional than E. coli for commodity foods.
Common Pitfalls:Equating modern lab use of E. coli with historical industrial practice.
Final Answer:Escherichia coli