Micro-organism used to produce lactic acid through fermentation process is known as............

Explanation

**Step-by-Step Solution:**

1. **Understanding the Process**: The question asks about the microorganism responsible for producing lactic acid through fermentation. This process is commonly associated with the production of curd from milk.

2. **Identifying the Microorganism**: The primary microorganism involved in lactic acid fermentation is a type of bacteria. In the context of curd production, we specifically look for the bacteria that convert lactose (the sugar found in milk) into lactic acid.

3. **Recognizing the Role of Lactobacillus**: The bacteria that are predominantly responsible for this fermentation process are known as Lactobacillus. When added to lukewarm milk, these bacteria ferment the lactose into lactic acid.

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