Bacteria play a crucial role in nutrient cycling by breaking down organic matter into simpler compounds, which can then be utilized by plants and other organisms. This process, known as decomposition, releases essential nutrients back into the ecosystem, such as nitrogen, phosphorus, and carbon, making them available for uptake by plants and other organisms. Additionally, some bacteria can also fix nitrogen from the atmosphere, converting it into a form that can be used by plants. Overall, bacteria are essential in maintaining nutrient balance and recycling in ecosystems.