干旱区生态环境知识资源中心

A novel Gram-negative bacterium, designated ZW(T), was isolated from a soil sample of the Western Desert of China, and its phenotypic properties and phylogenetic position were investigated using a polyphasic approach. Growth occurred on TGY medium at 5-42 degrees C with an optimum of 30 degrees C, and at pH 7.0-11.0 with an optimum of pH 9.0. The predominant cellular fatty acids were summed feature 3 (C-16:1 omega 7c/C-16:1 omega 6c or C-16:1 omega 6c/C-16:1 omega 7c) (39.22%), iso-C-15:0 (27.91%), iso-C-17:0 3OH (15.21%), C-16:0 (4.98%), iso-C-15:0 3OH (3.03%), C16:0 3OH (5.39%) and C-14:0 (1.74%). The major polar lipid of strain ZW(T) is phosphatidylethanolamine. The only menaquinone observed was MK-7. The GC content of the DNA of strain ZWT is 44.9 mol%. rDNA phylogeny, genome relatedness and chemotaxonomic characteristics all indicate that strain ZW(T) represents a novel species of the genus Sphingobacterium. We propose the name S. deserti sp. nov., with ZW(T) (= KCTC 32092T = ACCC 05744T) as the type strain. Whole genome optical mapping and next-generation sequencing was used to derive a finished genome sequence for strain ZW(T), consisting of a circular chromosome of 4,615,818 bp in size. The genome of strain ZW(T) features 3,391 protein-encoding and 48 tRNA-encoding genes. Comparison of the predicted proteome of ZW(T) with those of other sphingobacteria identified 925 species-unique proteins that may contribute to the adaptation of ZW(T) to its native, extremely arid and inhospitable environment. As the first finished genome sequence for any Sphingobacterium, our work will serve as a useful reference for subsequent sequencing and mapping efforts for additional strains and species within this genus.