Betaproteobacteria is a class of Proteobacteria. Betaproteobacteria are, like all Proteobacteria, gram-negative. The Betaproteobacteria consist of several groups of aerobic or facultative bacteria that are often highly versatile in their degradation capacities, but also contain chemolithotrophic genera (e.g., the ammonia-oxidising genus Nitrosomon...
class of Proteobacteria that are all eutrophs