The delta endotoxins are released, by which of the following organism that is most effectively used as biological control?

Options

A. Streptococcus
B. Staphylococcus
C. Lactobacillus
D. Saccharomyces

Answer

**Step-by-Step Solution:**

1. **Understanding Delta Endotoxins**: Delta endotoxins are specific proteins produced by certain bacteria that have insecticidal properties. They are particularly effective against various insect pests.

2. **Identifying the Organism**: The organism known for producing delta endotoxins is *Bacillus thuringiensis*, commonly abbreviated as Bt. This bacterium is widely recognized for its role in biological pest control.

3. **Biological Control Application**: *Bacillus thuringiensis* is utilized in agriculture as a biopesticide. The delta endotoxins produced by this bacterium are toxic to certain insects, making it an effective tool for controlling pest populations without harming beneficial insects.

4. **Transgenic Plants**: The genes responsible for the production of delta endotoxins can be incorporated into transgenic plants, making them resistant to insect pests. This genetic modification allows crops to produce their own insecticidal proteins, reducing the need for chemical pesticides.

5. **Example of Application**: One notable example of the application of delta endotoxins is in Bt cotton and Bt corn, which have been engineered to express these toxins and provide protection against specific insect pests.

6. **Conclusion**: Therefore, the organism that releases delta endotoxins and is most effectively used for biological control is *Bacillus thuringiensis*.

**Final Answer**: The delta endotoxins are released by the organism *Bacillus thuringiensis*.

---