Question

For the manufacture of gluconic acid and citric acid, which of the following microorganisms is used?
A. Lactobacillus bulgaricus
B. Acetobacter sp.
C. Aspergillus niger
D. Gluconobacter sp.

Answer 1

Gluconic Acid is the carboxylic acid created by the oxidation of the primary carbon of glucose with sterile and chelating properties. Gluconic acid found copiously in the plant, honey and wine can be made by fungal fermentation process commercially. Citric acid is a weak organic acid that is a natural preservative that is often used to give foods that soft drinks an acidic taste.

Complete answer:
Aspergillus niger is cultured for the engineering production of loads of substances. A variety of strains of A. niger are incorporated in the industrial preparation of citric acid and gluconic acid and have been evaluated as acceptable for everyday intake.
Lactobacillus bulgaricus is the major bacterium used for the manufacture of yogurt. Acetobacter sp. is illustrated by the ability to switch ethanol to acetic acid in the presence of oxygen. Gluconobacter favors sugar-rich environments so are occasionally found as a spoilage organism in beer.
Gluconic acid is formed, during glucose oxidation by mainly Aspergillus sps. A. niger fermentation is generally documented as protected by the United States Food and Drug Administration under the Federal Food, Drug, and Cosmetic Act.

Hence, the correct answer is option (C).

Note: Many functional enzymes are formed using the industrial fermentation of Aspergillus niger. For instance, Aspergillus niger glucoamylase is used in the formation of fructose corn syrup, and pectinases are utilized in cider and wine clarification. Alpha-galactosidase, an enzyme that ruptures down definite compound sugars, is a constituent of products that decrease flatulence. Aspergillus niger is also cultivated for the extraction of the enzyme, glucose oxidase, used in the design of glucose biosensors, due to its elevated affinity for $\beta$-D-glucose.