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

Abstract

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.