The large holes in 'Swiss cheese' are because of

Options

A. Propioni bacterium sharmanii
B. Saccharomyces cerevisiae
C. Trichoderma polysporum
D. Clostridium butylicum

Answer

### Step-by-Step Solution:

1. **Understanding Swiss Cheese**: Swiss cheese is known for its distinctive large holes, which are often referred to as "eyes." These holes are a unique characteristic of this type of cheese.

2. **Role of Bacteria**: The formation of these large holes is primarily due to the activity of specific bacteria during the cheese-making process.

3. **Lactic Acid Production**: Initially, other bacteria present in the cheese production process produce lactic acid. This lactic acid is crucial as it sets the stage for the next step in hole formation.

4. **Carbon Dioxide Production**: The bacteria responsible for the holes, specifically Propionibacterium, utilize the lactic acid produced by the other bacteria to generate carbon dioxide (CO2).

5. **Formation of Bubbles**: As the CO2 gas is produced, it accumulates and forms bubbles within the cheese. These bubbles are what create the characteristic holes or "eyes" in Swiss cheese.

6. **Terminology**: The holes in Swiss cheese are traditionally called "eyes." If cheese lacks these holes, it is referred to as "blind cheese."

7. **Identifying the Bacteria**: The specific bacteria responsible for the formation of these holes in Swiss cheese is known as Propionibacterium, particularly the species Propionibacterium freudenreichii.

### Final Answer:
The large holes in Swiss cheese are because of the activity of the bacteria Propionibacterium, which produces carbon dioxide gas during the fermentation process.

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