Sphingomonadaceae

Sphingomonadaceae are a gram-negative bacterial family of the Alphaproteobacteria. An important feature is the presence of sphingolipids (mainly 2′-hydroxymyristoyl dihydrosphingosine 1-glucuronic acid, "SGL-1") in the outer membrane of the cell wall.<ref name="BergeyAlpha2">Template:Cite book</ref><ref>Template:Cite journal</ref> The cells are ovoid or rod-shaped. Others are also pleomorphic, i.e. the cells change the shape over time. Some species from Sphingomonadaceae family are dominant components of biofilms.<ref>Template:Cite journal</ref><ref name=":12"/><ref>Template:Cite journal</ref>

Energy source

While most species within Sphingomonadaceae family are heterotrophic,<ref name=":02">Template:Cite book</ref> some are phototrophic.

Function

Some species of Sphingomonadaceae are known to degrade some aromatic compounds. This makes the bacteria of interest to environmental remediation.<ref name="The Prokaryotes2">Template:Cite book</ref>

The diverse metabolic capacity of genera within the Sphingomonadaceae family, such as Sphingobium, Novosphingobium,Template:Efn and Sphingopyxis enable these genera to adapt to and be abundant in the presence of bisphenol A. A microbial community with abundant Sphingomonadaceae members can degrade bisphenol A with a constant rate.<ref>Template:Cite journal</ref>

Some Sphingomonas species are able to produce sphingans, a kind of exopolysaccharides with certain viscosity. This property of sphingans makes it useful in many industries including food and pharmaceutical.<ref>Template:Cite journal</ref><ref name=":02"/>

Distribution

Bacteria within Sphingomonadaceae family are distributed in various environments, such as water,<ref name=":12">Template:Cite journal</ref> soil,<ref name=":2">Template:Cite journal</ref><ref name=":3">Template:Cite journal</ref> sediment.<ref name=":02"/><ref>Template:Cite journal</ref>

Phylogeny

The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature<ref name="LPSN"/> and the phylogeny is based on whole-genome sequences.<ref name="Hördt">Template:Cite journal</ref>Template:Efn

Interaction with human and plants

Some members of the Sphingomonadaceae commonly exist in human-impacted environments, including drinking water systems,<ref>Template:Cite journal</ref><ref name=":12"/> hospital and household tap water,<ref>Template:Cite journal</ref> and medical devices.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>

Most of the species of the Sphingomonadaceae are not known to be harmful to humans or plants.<ref name=":02"/> Some species can protect plants from disease-causing pathogens such as Thielaviopsis basicola, and Rhizoctonia solani.<ref name=":02"/><ref name=":3"/><ref name=":2"/><ref>Template:Cite journal</ref>

The Sphingomonas and Sphingobium genera tend to have higher antibiotic resistance compared with three other genera within the Sphingomonadaceae: Novosphingobium,Template:Efn Sphingopyxis, and Blastomonas.<ref name=":12"/> 

See also

• Dihydrosphingosine
• Glucuronic acid
• 2-Hydroxy acid, for 2′-hydroxymyristoyl
• Myristic acid, for 2′-hydroxymyristoyl