Question

Which microorganism is commonly used for industrial production of ethanol?

• A. Escherichia coli
• B. Bacillus subtilis
• C. Saccharomyces cerevisiae
• D. Lactobacillus

Hint:

The conversion of glucose to ethanol by yeast follows the stoichiometry: \(C_{6}H_{12}O_{6} \rightarrow 2C_{2}H_{5}OH + 2CO_{2}\).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Ethanol production at an industrial scale is achieved through the fermentation of sugars (like glucose or molasses) by specific microorganisms under anaerobic conditions.
Step 2: Detailed Explanation:
Saccharomyces cerevisiae, commonly known as brewer's yeast or baker's yeast, is the organism of choice for industrial ethanol production.
It possesses several desirable traits:
1. High fermentation rate and efficiency.
2. High tolerance to ethanol concentrations (up to \(12-15%\)).
3. Ability to grow at low pH, which reduces the risk of bacterial contamination.
- Escherichia coli (Option A) is a model bacterium used in molecular biology.
- Bacillus subtilis (Option B) is used for enzyme and antibiotic production.
- Lactobacillus (Option D) is used for lactic acid production (yogurt making).
Step 3: Final Answer:
Saccharomyces cerevisiae is the most common microorganism used globally for industrial-scale ethanol fermentation.