burkholderiales burkholderiales the burkholderiales are an order of 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, polaromonas, thiomonas, collimonas, hydrogenophaga, sphaerotilus, variovorax, acidovorax, rubrivivax and rhodoferax (both members of the photosynthetic purple nonsulfur bacteria), and herbaspirillum (capable of nitrogen-fixation). burkholderiales burkholderia pseudomallei colonies on a blood agar plate scientific classification domain: bacteria phylum: pseudomonadota class: betaproteobacteria order: burkholderialesgarrity et al., 2006 families alcaligenaceae burkholderiaceae comamonadaceae oxalobacteraceae sutterellaceae burkholderiales incertae sedis aquabacterium aquincola candidatus branchiomonas eleftheria ideonella inhella leptothrix methylibium mitsuaria paucibacter piscinibacter piscinibacterium rhizobacter rivibacter roseateles rubrivivax sphaerotilus tepidicella tepidimonas thiobacter thiomonas xylophilus