Phytohalomonas tamaricis gen. nov., sp. nov., an endophytic bacterium isolated from Tamarix ramosissima roots growing in Kumtag desert.

A gram-stain-negative, aerobic, non-spore-forming, rod-shaped, non-motile bacterium strain R4HLG17 was isolated from Tamarix ramosissima roots growing in Kumtag desert. The strain grew at salinities of 0-16% (w/v) NaCl (optimum 5-6%), pH 5-9 (optimum 7) and at 16-45 °C. Based on 16S rRNA gene sequence similarity, strain R4HLG17 belonged to the family Halomonadaceae and was most closely related to Halomonas lutea DSM 23508(95.1%), followed by Halotalea alkalilenta AW-7(94.8%), Salinicola acroporae S4-41(94.8%), Salinicola halophilus CG4.1(94.6%), and Larsenimonas salina M1-18(94.4%). Multilocus sequence analysis (MLSA) based on the partial sequences of 16S rRNA, atpA, gyrB, rpoD, and secA genes indicated that the strain R4HLG17 formed an independent and monophyletic branch related to other genera of Halomonadaceae, supporting its placement as a new genus in this family. The draft genome of strain R4HLG17 was 3.6 Mb with a total G + C content of 55.1%. The average nucleotide identity to Halomonas lutea DSM 23508 was 83.5%. Q-9 was detected as the major respiratory quinone and summed feature 8 (Cω7c/Cω6c), summed feature 3 (Cω7c/Cω6c), and C as predominant cellular fatty acids. On the basis of chemotaxonomic, phylogenetic, and phenotypic evidence, strain R4HLG17 is concluded to represent a novel species of a new genus within Halomonadaceae, for which the name Phytohalomonas tamaricis gen. nov., sp. nov., is proposed. The type strain is R4HLG17 (=ACCC 19929=KCTC 52415).