Rufibacter roseolus sp. nov. and Rufibacter aurantiacus sp. nov., isolated from desert soil.

Two novel bacterial strains, designated as SYSU D00344T and SYSU D00433T, were isolated from soil of Gurbantunggut Desert in Xinjiang, north-west PR China. Cells of both strains were Gram-stain-negative, aerobic, short-rod-shaped, catalase-positive and non-motile. Oxidase activities of SYSU D00344T and SYSU D00433T were negative and positive, respectively. Optimal growth occurred at 30 °C, with 0-0.5 % (w/v) NaCl and at pH 7.0. The results of phylogenetic analysis of 16S rRNA gene sequences indicated that they represented members of the genus Rufibacter and were closely related to Rufibacter hautae NBS58-1T. The results of phylogenomic analysis indicated that the two strains formed two independent and robust branches distinct from all reference type strains. The analyses of average nucleotide identity (ANI), digital DNA-DNA hybridisation (dDDH) values and 16S rRNA gene similarities between the two strains and their relatives further demonstrated that SYSU D00344T and SYSU D00433T represented two different novel genospecies. The polar lipids consisted of phosphatidylethanolamine, one unidentified glycolipid, two unidentified aminophospholipids, and two or four unidentified lipids. MK-7 was the only respiratory quinone. The major fatty acids (>10 %) for both strains were identified as iso-C15 : 0, anteiso-C15 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), as well as summed feature 4 (anteiso-C17 : 1B and/or iso-C17 : 1I) for SYSU D00344T and C16 : 1ω5c for SYSU D00433T. On the basis of the phylogenetic, phenotypic, chemotaxonomic and genotypic characteristics, we propose Rufibacter roseolus sp. nov. and Rufibacter aurantiacus sp. nov. as two novel species in the genus Rufibacter. The type strains are SYSU D00344T (=CGMCC 1.8625T=MCCC 1K04971T=KCTC 82274T) and SYSU D00433T (=CGMCC 1.8617T=MCCC 1K04982T=KCTC 82277T), respectively.

Sphingomonas arenae sp. nov., isolated from desert soil.

Two bacterial strains, designated as SYSU D00720T and SYSU D00722, were isolated from a desert sandy soil sample collected from Gurbantunggut Desert in Xinjiang, north-west China. Cells were Gram-stain-negative, aerobic, non-motile, rod-shaped, oxidase-positive and catalase-negative. Colonies were circular, opaque, convex, smooth, orange on Reasoner's 2A (R2A) agar. The isolates were found to grow at 4-45 °C (optimum, 28-30 °C), at pH 6.0-7.0 (optimum, 7.0) and with 0-1.5 % (w/v) NaCl (optimum, 0%). Growth was observed on R2A agar, Luria-Bertani agar and nutrient agar, but not on trypticase soy agar. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, sphingoglycolipid, two unidentified aminolipids, one unidentified glycolipid, one unidentified aminoglycolipid, one unidentified aminophospholipid, one unidentified phospholipid and two unidentified lipids. The main fatty acids (>10%) were C17 : 1 ω6c, summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and C16 : 0. The major respiratory quinone was ubiquinone-10 and the major polyamine was sym-homospermidine. The genomic DNA G+C content was 66.0 mol%. Strains SYSU D00720T and SYSU D00722 were nearly identical with a 16S rRNA gene sequence similarity of 99.6 %, and 100.0 % average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) values. Phylogenetic analyses clearly demonstrated that these two strains belonged to the same species of the genus Sphingomonas, and had highest sequence similarity to Sphingomonas lutea KCTC 23642T (97.3 %). The ANI, AAI and dDDH values of strains SYSU D00720T and SYSU D00722 to S. lutea KCTC 23642T were both 73.2, 69.9 and 19.2 %, respectively. Based on phylogenetic, phenotypic and chemotaxonomic distinctiveness, strains SYSU D00720T and SYSU D00722 represent a novel species of the genus Sphingomonas, for which the name Sphingomonas arenae sp. nov. is proposed. The type strain is SYSU D00720T (=MCCC 1K05154T=NBRC 115061T).

Sabulicella rubraurantiaca gen. nov., sp. nov., a new member of the family Acetobacteraceae, isolated from desert soil.

Strain SYSU D01096T was isolated from a sandy soil sample collected from Gurbantunggut Desert in Xinjiang, PR China. Phylogenetic analysis of the nearly full-length 16S rRNA gene sequence revealed that strain SYSU D01096T belonged to the family Acetobacteraceae and was closest to Rubritepida flocculans DSM 14296T (96.0% similarity). Cells of strain SYSU D01096T were observed to be non-motile, short rod-shaped and Gram-staining negative. The colonies were observed to be translucent, reddish orange, circular, convex and smooth. Growth occurred at 15-37 °C (optimum, 28-30 °C), pH 4.0-8.0 (optimum, pH 7.0) and 0-0.5% NaCl (w/v; optimum, 0%) on Reasoner's 2A medium. The predominant ubiquinone was identified as ubiquinone 9 and the major fatty acids were Summed Feature 8 (C18:1 ω7c and/or C18:1 ω6c) and C16:0. The polar lipids consisted of diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylglycerol (PG), one unidentified phospholipid (PL), three unidentified aminolipids (AL1-3) and one unidentified aminophospholipid (APL). The genomic DNA G + C content was 69.1%. Phylogenetic tree based on 16S rRNA gene sequences indicated strain SYSU D01096T represented an individual lineage in the family Acetobacteraceae, which was supported by 30 core gene-based phylogenomic tree. Based on the multi-analysis including physiological, chemotaxonomic and phylogenetic comparison, strain SYSU D01096T was proposed to represent a novel species of a novel genus, named Sabulicella rubraurantiaca gen. nov., sp. nov., within the family Acetobacteraceae. The type strain is SYSU D01096T (= CGMCC 1.8619T = KCTC 82268T = MCCC 1K04998T).

Arenibaculum pallidiluteum gen. nov., sp. nov., a novel bacterium in the family Azospirillaceae, isolated from desert soil, and reclassification of Skermanella xinjiangensis to a new genus Deserticella as Deserticella xinjiangensis comb. nov., and transfer of the genera Indioceanicola and Oleisolibacter from the family Rhodospirillaceae to the family Azospirillaceae.

A novel pale orange-coloured bacterium, designated strain SYSU D00532T, was isolated from sandy soil collected from the Gurbantunggut desert in Xinjiang, PR China. Cells of strain SYSU D00532T were found to be aerobic, Gram-stain-negative, oxidase-positive, catalase-positive, motile and rod-shaped with a single polar or subpolar flagellum. Growth occurred at 15-45 °C (optimum, 28-37 °C, pH 5.0-8.0 (optimum, pH 6.0-7.0) and with 0-1.5% NaCl (w/v; optimum, 0.5 %). The major polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and phosphatidylglycerol. Unidentified aminolipids, unidentified polar lipids, an unidentified aminophospholipid and an unidentified phospholipid were also detected. The major respiratory quinone was ubiquinone-10 and the major fatty acids were summed feature 8 (C18:1 ω7c and/or C18:1 ω6c), C16:0 and C19:0 cyclo ω8c. The genomic DNA G+C content was 69.8 mol%. Results of phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SYSU D00532T belonged to the family Azospirillaceae and showed 93.4% (Desertibacter roseus 2622T), 93.2% (Skermanella xinjiangensis 10-1-101T), 93.2% ('Skermanella rubra' YIM 93097T) and 92.4% (Desertibacter xinjiangensis M71T) similarities. Based on the phylogenetic, phenotypic and chemotaxonomic data, strain SYSU D00532T is proposed to represent a new species of a new genus, named Arenibaculum pallidiluteum gen. nov., sp. nov., within the family Azospirillaceae. The type strain is SYSU D00532T (=KCTC 82269T=CGMCC 1.18631T=MCCC 1K04984T). We also propose the reclassification of Skermanella xinjiangensis to a new genus Deserticella as Deserticella xinjiangensis comb. nov., and the transfer of the genera Indioceanicola and Oleisolibacter from the family Rhodospirillaceae to the family Azospirillaceaewe based on the phylogenetic results.