Which of these organisms helps in the formation of curd and cheese from milk?

Options

A. Penicillium
B. Azotobacter
C. Lactobacillus
D. Streptococcus

Answer

To answer the question "Which of these organisms helps in the formation of curd and cheese from milk?", we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Organisms**: The options provided are Penicillium, Azotobacter, Lactobacillus, and Stryptococcus.

2. **Analyze Each Organism**:
- **Penicillium**: This is a type of fungus that is primarily known for its role in producing antibiotics, not in curd or cheese formation.
- **Azotobacter**: This bacterium is involved in nitrogen fixation, which is the process of converting atmospheric nitrogen into a form that plants can use. It does not play a role in curd formation.
- **Lactobacillus**: This is a type of bacteria that ferments lactose (the sugar found in milk) into lactic acid. This process lowers the pH of the milk, causing the proteins to coagulate and form curd.
- **Stryptococcus**: While some species of Streptococcus can be involved in fermentation, they are not the primary organisms responsible for curd formation.

3. **Conclusion**: Based on the analysis, Lactobacillus is the organism that helps in the formation of curd and cheese from milk by converting lactose into lactic acid, leading to the coagulation of milk proteins.

4. **Final Answer**: The correct option is **Lactobacillus**.