Sulfate-reducing bacteria (SRB) are a group of microorganisms that thrive in environments lacking oxygen. They play a crucial role in the sulfur cycle by reducing sulfate to sulfide, a process that occurs in various habitats, including marine sediments, freshwater environments, and anaerobic digesters. SRB are important for nutrient recycling and can influence the chemistry of their surroundings. These bacteria are often found in environments rich in organic matter, where they contribute to the breakdown of complex compounds. While beneficial in natural ecosystems, SRB can also cause problems in industrial settings, such as corrosion of pipelines and wastewater treatment, due to the production of hydrogen sulfide, which is toxic and corrosive.