Question

The antibiotic chloromycetin is obtained from
A. Sclerotiana libertine
B. Aspergillus niger
C. Streptomyces griseus
D. Streptomyces venezuelae

Answer 1

Hint: This antibiotic is obtained from a soil actinomycete that produces the antibiotic chloramphenicol during its metabolism.
The antibiotic is employed within the treatment of a variety of bacterial infections like typhoid, cholera, and meningitis.

Complete answer: The biosynthesis of certain important chemical metabolites in Gram-positive bacteria of the genus Streptomyces is controlled at several levels, involving pleiotropic, and pathway-specific regulators.
In Streptomyces venezuelae biosynthesis of the antibiotic drug, chloromycetin was reported to be initiated in a medium that was limited in nitrogen sources.
It decreases the growth rate of bacteria by preventing them from producing important proteins that are essential for their survival.
This antibiotic is widely used as an eye ointment for treating conditions like conjunctivitis.

So, the correct answer is option D. Streptomyces venezuelae.

Note: Extensive studies on the genus of this bacteria has revealed that they produce a range of 'secondary metabolites' — chemicals that help the bacteria prosper by inhibiting rival microbes. They produce more than half of the useful antibiotics used in treating several bacterial diseases.