Sphingomonas and Related Genera

Abstract

The genus Sphingomonas was defined by Yabuuchi et al. (1990) as a group of Gram-negative, rod-shaped, chemoheterotrophic, strictly aerobic bacteria that possess ubiquinone 10 as the major respiratory quinone, contain glycosphingolipids (GSLs) instead of lipopolysaccharide in their cell envelopes, and typically produce yellow-pigmented colonies. By 2001, the genus included more than 20 species that were quite diverse in terms of their phylogenetic, ecological, and physiological properties. As a result, Takeuchi et al. (2001) subdivided Sphingomonas into four genera: Sphingomonas, Sphingobium, Novosphingobium and Sphingopyxis. These genera are referred to collectively as “sphingomonads” in this chapter. The sphingomonads are widely distributed in nature, having been isolated from many different aqueous and terrestrial habitats, as well as from plant root systems, clinical specimens, and other sources. Sphingomonads are metabolically versatile