Hoyosella suaedae sp. nov., a novel bacterium isolated from rhizosphere soil of Suaeda aralocaspica (Bunge) Freitag & Schütze.

ABSTRACT

A Gram-stain-positive, non-motile and coccus-shaped bacterium, designated strain LNNU 331112T, was isolated from the composite rhizosphere soil of the halophyte Suaeda aralocaspica (Bunge) Freitag and Schütze, which was collected in Xinjiang, north-west China. Growth occurred at 10-45 °C, pH 6.0-11.0 and in the presence of 0-10 % NaCl (w/v). Phylogenetic analysis based on the 16S rRNA gene sequence suggested that strain LNNU 331112T belonged to the genus Hoyosella and showed 95.6, 95.5 and 95.4 % sequence similarities to Hoyosella altamirensis DSM 45258T, Hoyosella subflava CGMCC 4.3532T and Hoyosella rhizosphaerae CGMCC 1.15478T, respectively. The estimated digital DNA-DNA hybridization relatedness values between strain LNNU 331112T and the type strains of H. altamirensis DSM 45258T, H. subflava CGMCC 4.3532T and H. rhizosphaerae CGMCC 1.15478T were 18.9, 19.3 and 18.3 %, respectively. The average nucleotide identity values between strain LNNU 331112T and H. altamirensis DSM 45258T, H. subflava CGMCC 4.3532T and H. rhizosphaerae CGMCC 1.15478T were 72.6, 72.7 and 72.3 %, respectively. The genome sequence of strain LNNU 331112T showed 69.0-72.3 % average amino acid identity values in comparison with the related genome sequences of three validly published Hoyosella species. The genome of strain LNNU 331112T was 3.47 Mb, with a DNA G+C content of 68.4 mol%. A total of 3182 genes were identified as protein-coding in strain LNNU 331112T. Genomic analysis revealed that a number of genes involved in osmotic pressure regulation, intracellular pH homeostasis and potassium (K+) uptake protein were found in strain LNNU 331112T. The predominant menaquinones were MK-8 (44.6 %) and MK-7 (55.4 %), which differentiated strain LNNU 331112T from other three recognized Hoyosella species. Major fatty acids (>10 %) were C17  1 ω8c (33.8 %), C16  0 (23.3 %), C17  0 (12.8 %) and summed feature 3 (12.9 %), which also clearly separated strain LNNU 331112T from three recognized Hoyosella species. The polar lipid profile of strain LNNU 331112T included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, one unidentified glycolipid, one unidentified phospholipid and two unidentified lipids. According to the results of phenotypic, chemotaxonomic and phylogenetic analyses, strain LNNU 331112T is considered to represent a novel species of the genus Hoyosella, for which the name Hoyosella suaedae sp. nov. is proposed. The type strain is LNNU 331112T (=KCTC 39808T=CGMCC 1.17107T=DSM 103463T).