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

Abstract

Four pink-pigmented, non-motile, Gram-staining-negative and moderately halophilic curved rods, designated strains SSL50T, 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-SP71T (99.3-99.5 % sequence similarity) and Spiribacter salinus M19-40T (96.5-96.7 %). Other related strains were Alkalilimnicola ehrlichii MLHE-1T (95.1-95.3 %), Arhodomonas recens RS91T (95.1-95.2 %) and Arhodomonas aquaeolei ATCC 49307T (95.0-95.1 %), all members of the family Ectothiorhodospiraceae. The major fatty acids were C18 : 1ω6c and/or C18 : 1ω7c, C16 : 0 and C12 : 0. The DNA G+C range was 64.0-66.3 mol%. The DNA-DNA hybridization values between strains SSL50T, SSL25, SSL97, SSL4 and S. piribacter. curvatus UAH-SP71T were 37-49 %. The average nucleotide identity (ANIb) values between the genome of strain SSL50T and those of the two other representatives of the genus Spiribacter, S. curvatus UAH-SP71T and S. salinus M19-40T, 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 SSL50T (=CECT 9117T=IBRC-M 11076T).