Question

Which one of the following microorganisms is used for the production of citric acid in industries?
A. Lactobacillus bulgaricus
B. Penicillium citrinum
C. Aspergillus niger
D. Rhizopus nigricans

Answer 1

Microorganisms also are known as microbes are microscopic organisms. They exist as unicellular, multicellular, or cell clusters. Microorganisms are spread widely in nature. These are beneficial to life but can also cause some serious harm. Microorganisms are such as bacteria, archaea, fungi, protozoa, viruses, and algae. Microbes and their activities are crucial to virtually all processes on earth. These play a significant role in biodegradation, nutrient cycle, food spoilage, climate change, cause, and control of the disease.

Complete answer:
The citric acid is tricarboxylic.It contains three carboxylic function groups. Tricarboxylic acid is the first metabolic product formed in the tricarboxylic acid cycle or Krebs cycle. Citric acid is the most essential organic acid formed in tonnage. It is generally used in the pharmaceutical and food industries. Citric acid is mainly produced by submerged fermentation using Aspergillus niger or Candida sp. from various sources of carbohydrates such as molasses and starch-based media.
-Aspergillus niger is a fungus.
-Lactobacillus bulgaricus is used in the production of lactic acid.
-Penicillium citrinum produces mycotoxin citrinin and cellulose digesting enzymes such as cellulase, endoglucanase, and xylulose.
-Rhizopus nigricans produce various organic acids such as fumaric acid, gluconic acid, oxalic acid, succinic acid, and acetic acid.

Hence, the correct answer is option (C).

Additional information:
-It is a weak acid that occurs naturally in citrus fruits.
-It is a natural preservative.
-Aspergillus niger causes black mold disease on certain vegetables and fruits like grapes, apricots, peanuts, and onion.
-It is a common contaminant of food.

Note: Microorganisms as the name suggests are microscopic organisms. Citric acid occurs naturally in citrus fruits. The citric acid is tricarboxylic. Citric acid is the most essential organic acid formed in tonnage. It is generally used in the pharmaceutical and food industries and is a natural preservative. Aspergillus niger is used for the formation of citric acid in industries. Microorganisms are both beneficial and harmful.