Salinivirga Fredricksonii Gen. Nov., Sp Nov., A Heterotrophic Halophile Isolated From A Photosynthetic Mat, A Member Of A Novel Lineage (Salinarimonadaceae Fam. Nov.) Within The Order Rhizobiales, And Reclassification Of The Genus Salinarimonas Liu Et Al. 2010 Into Salinarimonadaceae

A halophilic bacterial strain, HL-109(T), was isolated from the unicyanobacterial consortium UCC-O, which was obtained from the photosynthetic mat of Hot Lake (Washington, USA). A polyphasic approach using phenotypic, genotypic and chemotaxonomic data was used to classify the strain within the order Rhizobiales. The organism stained Gram-negative and was a moderate thermophile with a growth optimum of 45 degrees C. It was obligately aerobic, heterotrophic and halophilic, growing in both NaCl and MgSO4 brines. The novel isolate had a polymorphic cellular morphology of short rods with occasional branching, and cells were monotrichous. The major fatty acids detected were C-18 : 1, C-18 : 0, C-16 : 0 and C-18 : cyc. Phylogenetic analysis of the 16S rRNA gene placed the strain in the order Rhizobiales and it shared 94% identity with the type strain of its nearest relative, Salinarimonas ramus. Morphological, chemotaxonomic and phylogenetic results did not affiliate the novel organism with any of the families in the Rhizobiales; therefore, HL-109(T) is representative of a new lineage, for which the name Salinivirga fredricksonii gen. nov., sp. nov. is proposed, with the type strain HL-109(T) (=JCM 31876(T) =DSM 102886(T)). In addition, examination of the phylogenetics of strain HL-109(T) and its nearest relatives, Salinarimonas ramus and Salinarimonas rosea, demonstrates that these halophiles form a clade distinct from the described families of the Rhizobiales. We further propose the establishment of a new family, Salinarimonadaceae fam. nov., to accommodate the genera Salinivirga and Salinarimonas (the type genus of the family).