Citric acid is produced by:

Options

A. Aspergillus niger
B. Streptococcus lactis
C. Acetobacter suboxydans
D. Candida utilis

Answer

To determine which organism produces citric acid, we can analyze the options provided:

1. **Aspergillus niger**: This is a type of fungus known for its ability to produce citric acid commercially. It is widely used in the food industry for this purpose.

2. **Streptococcus lactis**: This bacterium is primarily involved in the fermentation process for dairy products such as buttermilk and cheese, but it does not produce citric acid.

3. **Acetobacter suboxydens**: This organism is known for its role in the production of vinegar and is also used in the commercial production of Vitamin C (ascorbic acid), not citric acid.

4. **Candida utilis**: This yeast is utilized in the production of food additives and other fermentation processes, but it is not known for producing citric acid.

Based on the analysis of these options, the correct answer is:

**Citric acid is produced by Aspergillus niger.**