Pseudoxanthomonas japonensis is a species of mesophilic, motile, strictly aerobic, Gram-negative, non-spore-forming, rod-shaped bacteria with one polar flagellum, first isolated from human urine, riverside urban soil and anaerobic digester. 12-3<sup>T</sup> (=CCUG 48231<sup>T</sup> =CIP 107388<sup>T</sup> =JCM 11525<sup>T</sup>) is the type strain.