Differentiate between the following pairs on the basis of what is given in the brackets :
Useful bacteria and Harmful bacteria (Example)

Explanation

### Step-by-Step Solution:

1. **Definition of Useful Bacteria**:
Useful bacteria are microorganisms that provide benefits to humans, animals, or the environment. They play crucial roles in various processes such as digestion, fermentation, and the production of antibiotics.

2. **Examples of Useful Bacteria**:
- **Streptomyces**: This bacterium is known for its role in producing antibiotics, such as streptomycin, which is used to treat various infections.
- **Lactobacillus**: Commonly found in yogurt and cheese, this bacterium helps in the fermentation process and contributes to food production.
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