___________ bacteria helps in settling of curd.

Explanation

**Step-by-Step Solution:**

1. **Identify the Bacteria**: The question asks for the type of bacteria that helps in the process of curd formation. The specific bacteria involved in this process is known as Lactobacillus.

2. **Understand the Role of Lactobacillus**: Lactobacillus is a type of lactic acid bacteria. It plays a crucial role in the fermentation of milk, which is the primary step in making curd.

3. **Process of Fermentation**: During the fermentation process, Lactobacillus acts on lactose (the sugar present in milk) and converts it into lactic acid. This process occurs through anaerobic respiration, meaning it does not require oxygen.

...