Question

Which of the following statements is correct?
A. Aspergillus niger is used for producing cyclosporin A.
B. Activated sludge is digested by aerobic bacteria to produce marsh gas.
C. Fleming Chain and Florey were awarded with the Nobel Prize for discovering penicillin.
D. BOD is the amount of oxygen produced by bacteria on decomposition.

Answer 1

Herbicide is a category of chemical agent that is mainly used to kill or control or inhibit the growth of unwanted plants such as pests, unwanted plant species, agricultural weeds, etc. Selective herbicides are used to kill selective weeds without damaging the main crop.

Complete answer:
Option A is incorrect as citric acid is produced generally by the process of submerged fermentation with the help of fungus Aspergillus niger or Candida sp. Whereas the Cyclosporine A is an antibiotic that is mainly produced by the process of submerged fermentation of aerobic fungus known as Trichoderma polysporum.
Option B is also incorrect as activated sludge is mainly digested with the help of anaerobic types of bacteria for the production of marsh gases in the process of treating wastewater.
Option D is also incorrect because the biochemical oxygen demand (BOD), which is known as the amount of, dissolved oxygen which is used by the microorganisms in the biological process of dissolving organic substances in water.
Correct option is C Fleming Chain and Florey, both awarded with Nobel Prize jointly, for discovering penicillin. Chain and Florey started purification and extraction of penicillin, and started producing in large amounts for the treatment of different bacterial diseases.

Hence, the correct answer is option (C).

Note: Howard Walter Florey and Ernst Boris Chain were the two scientists who studied most successfully on Alexander Fleming's discovery of penicillin, shared with him the Nobel Prize of 1945 in Physiology or Medicine. Florey and Chain carried on Alexander Fleming's study and in 1937 started studying the antibacterial properties of moulds. Chain started the purification and concentrated the penicillin extracted by a complex process of freeze drying the products again and again.