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
Journal Article - Open Access
NAVAL RESEARCH LAB WASHINGTON DC WASHINGTON United States
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A halophilic bacterial strain, HL-109T, 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 deg 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 sub 18 1, C sub 18 0, C sub 16 0 and C sub 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-109T is representative of a new lineage, for which the name Salinivirga fredricksonii gen. nov., sp. nov. is proposed, with the type strain HL-109T JCM 31876T DSM 102886T. In addition, examination of the phylogenetics of strain HL-109T 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.