Question

What is the reason behind production of large holes in 'Swiss Cheese' ?

• A. The production of large amount of $CO_2$ and $H_2$ by {Trichoderma polysporum}
• B. The production of large amount of $CO_2$ by {Clostridium butylicum}
• C. The production of large amount of $CO_2$ and $H_2$ by lactic acid bacteria called {Lactobacillus}
• D. The production of large amount of $CO_2$ by {Propionibacterium sharmanii}

Hint:

Logic Tip: Link the 'S' and 'P' in the names to remember them! \textbf{S}wiss cheese = \textbf{P}ropionibacterium \textbf{s}harmanii. Roquefort cheese = {Penicillium roqueforti} (fungi).

Answer 1

The Correct Option is D

Step 1 : Understanding the Question:
The question asks for the specific biological cause behind the distinctive large holes found in Swiss cheese. We need to identify the correct microorganism and the chemical byproduct of its metabolism that creates this unique texture.
Step 2 : Key Formulas and Approach:
The approach involves identifying the specific bacterium and gas involved in the industrial production of Swiss cheese:
1. Microbe Identification: {Propionibacterium sharmanii}.
2. Metabolic Process: Fermentation of lactate.
3. Gaseous Byproduct: Carbon dioxide ($CO_2$).
4. Physical effect: Trapped gas bubbles create "eyes" or holes in the cheese curd.
Step 3 : Detailed Explanation:

Microbial Specificity: Different varieties of cheese are characterized by their unique texture, flavor, and taste, which are determined by the specific microbes used. In the case of Swiss cheese, the ripening process involves the bacterium {Propionibacterium sharmanii}.

Fermentation Pathway: As this bacterium ferments the lactate within the developing cheese, it undergoes a metabolic pathway that results in the production of large amounts of Carbon dioxide ($CO_2$).

Formation of Holes: Because the cheese is a semi-solid matrix, the $CO_2$ gas cannot easily escape. Instead, it accumulates in pockets. As the cheese firms up and ages, these gas bubbles leave behind the large, characteristic holes (often called "eyes") that define Swiss cheese.

Evaluation of Alternatives:
{Trichoderma polysporum} is a fungus used to produce the drug Cyclosporin A.

{Clostridium butylicum} is used for butyric acid production.

{Lactobacillus} is primarily used to make curd from milk and does not produce large $CO_2$ bubbles.


Step 4 : Final Answer:
The large holes in Swiss cheese are the result of the massive production of $CO_2$ gas by the bacterium {Propionibacterium sharmanii}. Therefore, the correct option is (D).