Galbibacter kalidii sp. nov., a flexirubin-type pigment-producing bacterium, isolated from saline soil in Xinjiang

A Gram-stain-negative, strictly aerobic, rod-shaped bacterium, designated EGI 63066^T, was isolated from a saline soil of Kalidium foliatum (Pall.), collected from Wujiaqu in Xinjiang, China. Strain EGI 63066^T is a non-motile, rod-shaped bacterium; it forms pale yellow colonies on the marine agar and grows at 10-37 °C,at pH 6.0-9.0 and 0-10% (w/v) NaCl. The 16S rRNA sequences of the strain EGI 63066^T and Galbibacter mesophilus Mok-17^T, Robertkochia solimangrovi CL23^T, Robertkochia sediminum 1368^T and Galbibacter pacificus CMA-7^T share sequence similarities of 92.80%, 91.85%, 91.79% and 91.79%, respectively. Higher average amino acid identity values with Galbibacter (72.10-76.90%) than with Robertkochia (69.40-70.30%) supported the assignment of strain EGI 63066^T to the genus Galbibacter. Phylogenomic analysis based on core genes revealed that strain Galbibacter kalidii formed a stable clade with the four recognized species of the genus Galbibacter and the not validly published 'Joostella atrarenae' M1-2. The average nucleotide identity and digital DNA-DNA hybridization values between the strain EGI 63066^T and members of the genus Galbibacter were 71.10-74.15% and 18.00-19.70%, respectively. The DNA G+C content of the genome for strain EGI 63066^T based on genomic DNA was 39.0 mol%, and the genome size was 4.66 Mbp. The predominant fatty acids of strain EGI 63066^T were iso-C_{15 : 0}, iso-C_{15 : 1} G and summed feature 3 (C_{16 : 1} ω6c and/or C_{16 : 1} ω7c). The major respiratory quinone was menaquinone-6, and the major polar lipids were phosphatidylethanolamine, aminolipid, aminophospholipid and phospholipid. Compared to other species within the genus Galbibacter, EGI 63066^T exhibits distinctive features, including the production of flexirubin-type pigments, CM-cellulose hydrolysis and whole-cell protein profiles. Based on the polyphasic taxonomic analysis, strain EGI 63066^T represents a novel species of the genus Galbibacter, for which the name G. kalidii sp. nov. is proposed. The type strain is EGI 63066^T (=JCM 36938^T=CGMCC 1.19132^T).