Antibiotics are chemicals made BY microbes that kill or stop OTHER microbes. The two you must know for NEET: Penicillin comes from a fungus, Penicillium notatum (later chrysogenum); Streptomycin, Tetracycline and many others come from a soil bacterium group called Streptomyces. Memory hook: "Penicillin = Penicillium (both start with Peni), Strepto-mycin = Strepto-myces (both start with Strepto)."
Match each antibiotic to its source microbe: Penicillin comes from the fungus Penicillium notatum, while Streptomycin and Tetracycline come from the bacterium Streptomyces. The names rhyme with their sources, which is the fastest way to remember them for NEET.
Your doubts, answered
Is Penicillin made by a bacterium or a fungus?
By a FUNGUS. Penicillin is produced by the mould (fungus) Penicillium notatum, discovered by Alexander Fleming. NEET often tries to trick you by calling it a bacterium. Remember: Penicillium is a fungus (mould), so its product Penicillin is a fungal antibiotic.
Which microbe makes Streptomycin?
A bacterium called Streptomyces. Note the spelling: the microbe is Streptomyces (a filamentous soil bacterium, an actinomycete) and the antibiotic is Streptomycin. Many antibiotics like Tetracycline, Erythromycin, Chloramphenicol and Neomycin also come from Streptomyces species.
Do microbes really make antibiotics, or are antibiotics man-made chemicals?
Microbes make them naturally. The word antibiotic means 'anti' (against) + 'bios' (life) of harmful microbes. NCERT clearly says antibiotics are chemicals PRODUCED by some microbes that can kill or stop the growth of other disease-causing microbes. We only grow the microbe in large tanks (fermentors) and purify the chemical.
What is the difference between Penicillium notatum and Penicillium chrysogenum?
Fleming's original discovery was from Penicillium notatum. For large-scale industrial production, a higher-yielding species, Penicillium chrysogenum, is now used. For NEET, NCERT mentions Penicillium notatum for the discovery, so that is the safest answer unless the question specifically asks about industrial production.
Who established Penicillin as a real medicine after Fleming?
Fleming only discovered it by chance in 1928. Its full use as an effective antibiotic was established later by Ernest Chain and Howard Florey. Fleming, Chain and Florey shared the Nobel Prize in 1945. Penicillin was used to treat wounded soldiers in World War II.
⚠️ The NEET trap ✗ Penicillin is produced by a bacterium named Penicillium. ✓ Penicillin is produced by a FUNGUS (mould) named Penicillium notatum. Penicillium is not a bacterium. 🧠 '-ium' fungus, not bacterium: Penicillium = mould. Streptomyces (the bacterium) makes Streptomycin, NOT Penicillin.
Real NEET questions
NEET 2017
Which of the following is correctly matched for the product produced by them?
A · Acetobacter aceti : Antibiotics
B · Methanobacterium : Lactic acid
C · Penicillium notatum : Acetic acid
D · Saccharomyces cerevisiae : Ethanol ✓
Solution: Only Saccharomyces cerevisiae : Ethanol is correct (yeast makes ethanol during fermentation). The trap options are all swapped: Penicillium notatum makes the ANTIBIOTIC Penicillin, not acetic acid; Acetobacter aceti makes acetic acid, not antibiotics; Methanobacterium makes methane, not lactic acid. Knowing Penicillium notatum is an antibiotic source lets you reject option (c) at once.
Solved Microbes in Human Welfare NEET PYQs
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Name two antibiotics and their source microbes for NEET.
Penicillin from the fungus Penicillium notatum, and Streptomycin (also Tetracycline) from the bacterium Streptomyces.
Is Streptomyces a bacterium or a fungus?
Streptomyces is a bacterium (a filamentous, soil-living actinomycete), even though it looks thread-like. It is the biggest natural source of antibiotics.
What does the word 'antibiotic' mean?
'Anti' means against and 'bios' means life. An antibiotic is a microbial chemical that acts against the life (growth) of other harmful microbes.
Which antibiotic was discovered first and by whom?
Penicillin was the first antibiotic, discovered by chance in 1928 by Alexander Fleming from the mould Penicillium notatum.
Are all antibiotics from fungi?
No. Penicillin is from a fungus, but most other antibiotics (Streptomycin, Tetracycline, Erythromycin, Chloramphenicol) are from bacteria of the genus Streptomyces.
