Bacteria play many roles in our ecosystem. Bacteria are decomposers which break down dead material and recycle it. They also can be producers, making food from sunlight, such as photosynthetic bacteria, or chemicals, such as chemosynthetic bacteria. Bacteria play important roles in the global ecosystem for cycling of nutrients such as carbon, nitrogen, and sulfur is completed by their ceaseless labor. Organic carbon, in the form of dead and rotting organisms, would quickly deplete the carbon dioxide in the atmosphere if not for the activity of decomposers. This is because microorganisms decompose dead organic waste of plants and animals converting them into simple substances. These substances are again used by other plants and animals. Thus, microorganisms can be used to degrade harmful and odourific substances and clean up the environment. Bacteria break down dead organisms, animal waste, and plant litter to obtain nutrients. But microbes don't just eat nature's waste, they recycle it. The process of decomposition releases chemicals that can be used to build new plants and animals.

The most significant effect of the microbes on earth is their ability to recycle the primary elements that make up all living systems, especially carbon, oxygen, and nitrogen. Primary production involves photosynthetic organisms which take up CO2 from the atmosphere and convert it to organic material. Bacteria are single-celled microbes without a nucleus. Bacteria play many roles in our ecosystem. Bacteria are decomposers which break down dead material and recycle it. They also can be producers, making food from sunlight, such as photosynthetic bacteria, or chemicals, such as chemosynthetic bacteria.The cycling of nutrients such as carbon, nitrogen, and sulfur is completed by their ceaseless labor. Organic carbon, in the form of dead and rotting organisms, would quickly deplete the carbon dioxide in the atmosphere if not for the activity of decomposers. Bacteria break down dead organisms, animal waste, and plant litter to obtain nutrients. But microbes don't just eat nature's waste, they recycle it. The process of decomposition releases chemicals that can be used to build new plants and animals. Decomposers have the ability to break down dead organisms into smaller particles and create new compounds. We use decomposers to restore the natural nutrient cycle through controlled composting. Decomposers are the link that keeps the circle of life in motion. They perform a valuable service as Earth's cleanup crew. Without decomposers, dead leaves, dead insects, and dead animals would pile up everywhere. Imagine what the world would look like! More importantly, decomposers make vital nutrients available to an ecosystem's primary producers usually plants and algae. Microorganism can act as magic bullets for bioremediation of contaminated sites and biodegradation purposes. Now a day microorganisms are effectively used together with nanotechnology, termed as nano-bioremediation to clean up radioactive wastes.