Which of the following microbe is used for making bread?

The correct answer is Option (2) → Saccharomyces cerevisiae

Option (1) Propionibacterium sharmanii — Incorrect. This bacterium is used for Swiss cheese; the CO₂ it makes gives the cheese its large holes.

Option (2) Saccharomyces cerevisiae — Correct. Baker's yeast ferments the dough; the CO₂ it releases makes the dough rise.

Option (3) Aspergillus niger — Incorrect. This fungus is used to make citric acid.

Option (4) Trichoderma Polysporum — Incorrect. This fungus gives cyclosporin A, an immunosuppressive drug used in organ transplants.

NCERT Extract:
Microbes in Household Products – “… The dough, which is used for making foods such as dosa and idli is also fermented by bacteria. The puffed-up appearance of dough is due to the production of CO2 gas. … Where do you think the bacteria for these fermentations come from? Similarly the dough, which is used for making bread, is fermented using baker’s yeast (Saccharomyces cerevisiae).”