Spiribacter roseus sp nov., a moderately halophilic species of the genus Spiribacter from salterns

Four pink-pigmented, non-motile, Gram-staining-negative and moderately halophilic curved rods, designated strains SSL50(T), SSL25, SSL97 and SSL4, were isolated from a saltern located in Isla Cristina, Huelva, south-west Spain. Phylogenetic analyses based on 16S rRNA gene sequences showed that they were members of the genus Spiribacter, most closely related to Spiribacter curvatus UAH-SP71(T) (99.3-99.5% sequence similarity) and Spiribacter salinus M19-40(T) (96.5-96.7 %). Other related strains were Alkalilimnicola ehrlichii MLHE-1(T) (95.1-95.3 %), Arhodomonas recens RS91(T) (95.1-95.2 %) and Arhodomonas aquaeolei ATCC 49307(T) (95.0-95.1 %), all members of the family Ectothiorhodospiraceae. The major fatty acids were C-18 (:) (1 omega)6c and/or C-18 (:) (1 omega)7c, C-16 (:) (0) and C-12 (:) (0). The DNA G+C range was 64.0-66.3 mol%. The DNA-DNA hybridization values between strains SSL50(T), SSL25, SSL97, SSL4 and S. piribacter. curvatus UAH-SP71(T) were 37-49 %. The average nucleotide identity (ANIb) values between the genome of strain SSL50(T) and those of the two other representatives of the genus Spiribacter, S. curvatus UAH-SP71(T) and S. salinus M19-40(T), were 82.4% and 79.1 %, respectively, supporting the proposal of a novel species of the genus Spiribacter. On the basis of the polyphasic analysis, the four new isolates are considered to represent a novel species of the genus Spiribacter, for which the name Spiribacter roseus sp. nov. is proposed. The type strain is SSL50(T) (= CECT 9117(T) = IBRC-M 11076(T)).