Xanthomonadales
Xanthomonadales is an order of Gram-negative, chemoorganotrophic bacteria within the class Gammaproteobacteria of the phylum Proteobacteria. The order encompasses several families, most notably Xanthomonadaceae and Pseudoxanthomonadaceae, and contains a variety of genera including Xanthomonas, Xylella, Stenotrophomonas, and Pseudoxanthomonas. Members are predominantly aerobic or facultatively anaerobic, and most are rod-shaped or ovoid. They are usually motile, frequently by a single polar flagellum, though some species are nonmotile. Biochemical traits commonly include catalase positivity and oxidase negativity, and many strains are capable of utilizing a range of organic substrates.
A distinctive feature of many Xanthomonadales is pigment production; several genera, especially Xanthomonas, synthesize yellow pigments
Ecologically, Xanthomonadales includes important plant-associated bacteria. Numerous Xanthomonas species are plant pathogens causing diseases such as
Taxonomically, Xanthomonadales has undergone revisions with molecular data (16S rRNA gene sequencing and whole-genome analyses) refining