The large holes in “Swiss cheese” are formed due to the production of large amounts of carbon dioxide by a microbe:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Propionibacterium sharmanii
Different kinds of cheese get their texture, flavour and taste from the microbes used to make them. The large holes in ‘Swiss cheese’ come from the large amount of CO2 produced by the bacterium Propionibacterium sharmanii. The gas is trapped inside the cheese as bubbles.
(1) Trichoderma polysporum — Incorrect. This fungus produces cyclosporin A, a drug that suppresses the immune system in organ-transplant patients.
(2) Saccharomyces cerevisiae — Incorrect. This is baker’s yeast. Its CO2 puffs up bread dough, but it is not the microbe of Swiss cheese.
(3) Propionibacterium sharmanii — Correct. Its CO2 makes the large holes of Swiss cheese.
(4) Escherichia coli — Incorrect. E. coli is a bacterium of the human gut and a common host in biotechnology. It is not used to make cheese.
NCERT Extract:
Microbes in Household Products – …
