A large number of antibiotics have been isolated from

Options

A. Bacteria actinomycetes
B. Acids
C. Alkanals
D. Bacteria rhizobium

Answer

**Step-by-Step Text Solution:**

1. **Understanding Antibiotics**: Antibiotics are substances that can inhibit the growth of or kill bacteria. They are widely used in medicine to treat bacterial infections.

2. **Sources of Antibiotics**: A large number of antibiotics are derived from natural sources. The primary sources include certain types of bacteria and fungi.

3. **Identifying the Correct Options**: The question provides four options:
- A) Bacteria
- B) Actinomycetes
- C) Acids
- D) Alkalines
- E) Rhizobium

4. **Analyzing the Options**:
- **Bacteria**: This is a broad category that includes many microorganisms, some of which produce antibiotics.
- **Actinomycetes**: This is a specific group of bacteria known for their ability to produce a variety of antibiotics, such as streptomycin and tetracycline.
- **Acids and Alkalines**: These are not sources of antibiotics.
- **Rhizobium**: This is a genus of bacteria known for nitrogen fixation, not primarily for antibiotic production.

5. **Conclusion**: The correct answer is a combination of bacteria and actinomycetes, as they are well-known sources of antibiotics.

**Final Answer**: A large number of antibiotics have been isolated from **bacteria and actinomycetes**.

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