Bacterial Metabolism and Relationships
Bacteria have evolved diverse metabolic strategies to obtain energy and carbon. Photoautotrophs like cyanobacteria use sunlight to convert CO₂ into organic compounds, similar to plants. While cyanobacteria produce oxygen, other bacteria use bacteriochlorophyll and don't release O₂, thriving in oxygen-free environments.
Chemoautotrophs get their energy by oxidizing inorganic compounds like H₂ and NH₃, while chemoheterotrophs obtain carbon and energy from organic nutrients made by other organisms. Some bacteria, called photoheterotrophs, combine both worlds by using light for energy but getting carbon from organic compounds.
Bacteria also form important relationships with other organisms. These include mutually beneficial relationships (mutualism), one-sided benefits (commensalism), or relationships where bacteria benefit at the expense of others (parasitism). Many bacteria are involved in nitrogen metabolism, with some able to convert atmospheric nitrogen into forms other organisms can use—a process called nitrogen fixation.
Fun Fact: Saprotrophs are nature's recycling crew! These bacteria break down dead organic matter, returning valuable nutrients to the ecosystem and preventing the world from being buried under fallen leaves and dead organisms.
