 Together, the "Betaproteobacteria" represent a broad variety of metabolic strategies and occupy diverse environments from obligate pathogens living within host organisms to oligotrophic groundwater ecosystems.Whilst most members of the "Betaproteobacteria" are heterotrophic, deriving both their carbon and electrons from organocarbon sources, some are photoheterotrophic, deriving energy from light and carbon from organocarbon sources.Other genera are autotrophic, deriving their carbon from bicarbonate or carbon dioxide and their electrons from reduced inorganic ions such as nitrite, ammonium, thiosulfate or sulfide — many of these chemolithoautotrophic.