Here's why:

* Decomposers break down dead organisms and waste: Bacteria play a crucial role in breaking down dead plants and animals, as well as waste products like feces and urine. They do this by releasing enzymes that digest the complex molecules in these materials.

* Recycling nutrients: The breakdown of dead organisms and waste by bacteria releases nutrients back into the environment, making them available for other organisms to use. This process is essential for maintaining the balance of ecosystems.

* Examples of decomposer bacteria: Examples of bacteria that act as decomposers include saprophytes which feed on dead organic matter, and nitrogen-fixing bacteria which convert atmospheric nitrogen into forms usable by plants.

In summary, bacteria are essential decomposers that play a vital role in the recycling of nutrients within ecosystems.