Betaproteobacteria

Betaproteobacteria are a class of Gram-negative bacteria, and one of the six classes of the phylum Pseudomonadota (synonym Proteobacteria).

The Burkholderiales are an order of Betaproteobacteria in the phylum Pseudomonadota. Like all Pseudomonadota, they are Gram-negative. They include several pathogenic bacteria, including species of Burkholderia, Bordetella, and Ralstonia. They also include Oxalobacter and related genera, which are unusual in using oxalic acid as their source of carbon. Other well-studied genera include Alcaligenes, Cupriavidus, Achromobacter, Comamonas, Delftia, Massilia, Duganella, Janthinobacterium, Polynucleobacter (important freshwater bacterioplankton), non-pathogenic Paraburkholderia, Caballeronia, Polaro

The Nitrosomonadales are an order of the class Betaproteobacteria in the phylum Pseudomonadota. Like all members of their class, they are Gram-negative.

The Methylophilaceae are a family of Pseudomonadota, given their own order. Like all Pseudomonadota, they are Gram-negative. The cells are slightly curved or straight rod-shaped.