The discovery of penicillin earned Alexander Fleming, Ernst Chain, and Howard Florey the Nobel Prize in which year?

1945

The correct answer is Option (3) - 1945

The discovery of penicillin earned Alexander Fleming, Ernst Chain, and Howard Florey the Nobel Prize in Physiology or Medicine in 1945.

Antibiotics produced by microbes are regarded as one of the most significant discoveries of the twentieth century and have greatly contributed towards the welfare of the human society. Antibiotics are chemical substances, which are produced by some microbes and can kill or retard the growth of other (disease-causing) microbes.

Alexander Fleming while working on Staphylococci bacteria, once observed a mould growing in one of his unwashed culture
plates around which Staphylococci could not grow. He found out that it was due to a chemical produced by the mould and he named it Penicillin after the mould Penicillium notatum. However, its full potential as an effective antibiotic was established much later by Ernest Chain and Howard Florey. This antibiotic was extensively used to treat American soldiers wounded in World War II. Fleming, Chain and Florey were awarded the Nobel Prize in 1945, for this discovery.