Description of Thalassospira lohafexi sp nov., isolated from Southern Ocean, Antarctica

A gram-negative, aerobic, obligatory halophilic, curved-to-spiral rod-shaped, uni- or bi-polar flagellated motile bacterium 139Z-12(T) was isolated from water samples collected from Southern Ocean surrounding Antarctica as part of the Indo-German iron fertilization experiment "LOHAFEX." The bacterium was positive for catalase, oxidase, and gelatinase, with C-18:1 omega 7c (20.1 %), C-16:0 (7.3 %), C-16:1 omega 7c (28.9 %), and C-12:0 (19.0 %) as the predominant fatty acids, phosphatidylglycerol, and phosphatidylethanolamine as major lipids and Q-10 as the major respiratory quinone. DNA G + C content (mol%) of strain 139Z-12(T) was 53.0. Both BLAST and EzTaxon identified strain 139Z-12(T) as affiliated species of the genus Thalassospira with 16S rRNA gene sequence similarities ranging from 97.9 to 99.9 %. Based on above characteristics, strain 139Z-12(T) was assigned to the genus Thalassospira. Since strain 139Z-12(T) shared a DNA-DNA similarity of < 70.0 % with members of the genus Thalassospira, 139Z-12(T) was identified as a novel species of the genus and named as Thalassospira lohafexi sp. nov. In addition to this, strain 139Z-12(T), based on REP-PCR, delineated at a similarity coefficient of < 0.67 from other species of the genus Thalassospira and also exhibited a MLSA distance of < 95.5 %, a value less than the interspecies distance determined previously for the genus Thalassospira, further supporting the species status. In addition, species rank was further confirmed by other polyphasic characteristics. The type strain of Thalassospira lohafexi sp. nov. is 139Z-12(T) (KCTC 32347(T) = LMG 27449(T) = MCC 2233(T) = NBRC 110402(T)).