Step 1: Understanding the production of citric acid: - Citric acid is commonly used in food and pharmaceutical industries. The production of citric acid is an important biotechnological process, usually carried out by fungi under aerobic conditions.
- Several microorganisms are used for citric acid production, but the most widely used microorganism is Aspergillus niger, a fungus.
Step 2: Explanation of the options:
- Option (A) Aspergillus niger: This microorganism is the most commonly used in the industrial production of citric acid due to its ability to efficiently produce citric acid during fermentation processes.
- Option (B) Lactobacillus sp.: While Lactobacillus species are important for lactic acid production, they are not used for citric acid production.
- Option (C) Clostridium butylicum: This bacterium is involved in butyric acid production, not citric acid.
- Option (D) Saccharomyces cerevisiae: This yeast is primarily used for ethanol production, not citric acid production.
Step 3: Conclusion:
The correct microbe used for the commercial and industrial production of citric acid is Aspergillus niger. Hence, the correct answer is option (A).