Green non-sulfur bacteria are a group of photosynthetic bacteria that do not use sulfur compounds for their energy needs. Instead, they utilize organic compounds and light to produce energy through a process called anoxygenic photosynthesis. These bacteria are typically found in environments such as hot springs and mud, where light is available but oxygen levels are low. These bacteria are important for their role in ecosystems, as they contribute to the cycling of nutrients and can help in the breakdown of organic matter. They are also studied for their potential applications in biotechnology, including biofuels and bioremediation.