A novel bacterium, designated TRT317T, was isolated from saline-alkaline soil collected from the Pamir plateau in northwest China. Cells of this strain were Gram-stain-negative, aerobic rods and red-pink-coloured. Phylogenetic analysis using 16S rRNA gene sequences indicated that strain TRT317T showed the highest sequence similarity to the type strains of Pontibacter diazotrophicus (96.3 %) and Pontibacter yuliensis (96.2 %). Growth was observed at 4-40 °C, pH 6.0-10.0 and in the presence of up to 7 % (w/v) NaCl. The major fatty acids were iso-C15 : 0 and summed feature 4 (iso-C17 : 1 I/anteiso-C17 : 1 B). The polar lipids included phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified phospholipid, four unidentified glycolipids and five unidentified lipids. The whole-cell sugars of strain TRT317T were mannose, rhamnose, glucose, galactose, xylose, arabinose and four unidentified sugars. The sole respiratory quinone was MK-7. The genomic DNA G+C content of strain TRT317T was 47.7 mol%. The average nucleotide identity (ANI) value of strain TRT317T with P. diazotrophicus was 88.3 %, which is below the standard ANI threshold for species identification (95-96 %). Combined results of physiological, genotypic, phylogenetic and chemotaxonomic analyses demonstrated that strain TRT317T represents a novel species within the genus Pontibacter, for which the name Pontibacter pamirensis sp. nov. is proposed. The type strain is TRT317T (=CGMCC1.18690T=KCTC 82818T).
Keywords: Pamir plateau; Pontibacter pamirensis sp. nov.; polyphasic taxonomy; saline-alkaline soil.