prokaryotes - bacteria see Domain Bacteria Woese et al. 1990 Domain "Bacteria" Woese et al. 1990 Phylum "Proteobacteria" Garrity et al. 2005 see Superphylum Proteobacteria Craig et al. 2010 Class Betaproteobacteria Garrity et al. 2006 Order Burkholderiales Garrity et al. 2006 Family Burkholderiaceae Garrity et al. 2006 Genus Polynucleobacter Heckmann and Schmidt 1987