The antibiotic penicillin, widely used to treat bacterial infections, is naturally obtained from which type of organism in industrial production?

Introduction / Context:
Penicillin is one of the first antibiotics discovered and has saved countless lives by treating bacterial infections. This question asks you to identify the natural source organism from which penicillin is obtained. Understanding that penicillin was originally derived from a fungus helps highlight the importance of microorganisms in medicine and biotechnology.

Given Data / Assumptions:
- Penicillin is an antibiotic used to kill or inhibit bacteria.- The options include synthetic processes, bacteria, fungi, virus infected cells and algae.- The question focuses on the organism from which penicillin is obtained in nature and industrial production.- Basic historical knowledge of penicillin discovery is assumed.

Concept / Approach:
Penicillin was first discovered by Alexander Fleming, who observed that a mould contaminating a bacterial culture inhibited bacterial growth. The mould belonged to the genus Penicillium. Later industrial processes grew Penicillium species in large fermentation tanks to produce penicillin on a large scale. Although many modern antibiotics can be chemically modified or synthesised, the original source of penicillin is a fungus, not a bacterium or algae. Virus infected cells are used for vaccine production, not for penicillin. Therefore, the correct answer is that penicillin is obtained from a fungus of the genus Penicillium.

Step-by-Step Solution:
Step 1: Recall the classic story where Fleming noticed a zone of inhibition around a fungal colony on a bacterial plate.Step 2: Remember that this fungus was identified as Penicillium notatum, later replaced in industry by Penicillium chrysogenum and related species.Step 3: Recognise that these are moulds, which are filamentous fungi.Step 4: Examine the options and identify which one correctly describes a fungal source.Step 5: Select option C, a fungus of the genus Penicillium grown in fermentation tanks, as the correct answer.

Verification / Alternative check:
Microbiology textbooks describe Penicillium species as producers of penicillin and often show images of the characteristic greenish mould.Industrial microbiology references explain how Penicillium cultures are maintained in controlled bioreactors to produce penicillin, which is then extracted and purified.No source describes penicillin as primarily synthetic from the beginning or produced by algae or viruses, confirming the fungal origin.

Why Other Options Are Wrong:
Option A is wrong because although penicillin can be chemically modified, its original and main industrial source is not a purely synthetic process but fermentation using fungi.Option B is wrong because most bacteria are targets of penicillin rather than producers of this antibiotic.Option D is wrong because virus infected cells in culture are used mainly for vaccine and viral product production, not for penicillin.Option E is wrong because algae are employed in some biofuel and food applications but are not known sources of penicillin.

Common Pitfalls:
Students sometimes assume that all antibiotics come from bacteria, since many later antibiotics were discovered in actinomycete bacteria like Streptomyces.Another pitfall is to think of modern synthetic drug production and forget the natural microbial origins of classical antibiotics.To remember penicillin correctly, connect the word Penicillium with penicillin and the idea of a green mould growing on old bread or fruit.

Final Answer:
The antibiotic penicillin is naturally obtained from a fungus of the genus Penicillium that is grown in industrial fermentation tanks.