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-12T 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 C18:1ω7c (20.1 %), C16:0 (7.3 %), C16:1ω7c (28.9 %), and C12:0 (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-12T was 53.0. Both BLAST and EzTaxon identified strain 139Z-12T 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-12T was assigned to the genus Thalassospira. Since strain 139Z-12T shared a DNA–DNA similarity of <70.0 % with members of the genus Thalassospira, 139Z-12T was identified as a novel species of the genus and named as Thalassospira lohafexi sp. nov. In addition to this, strain 139Z-12T, 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-12T (KCTC 32347T = LMG 27449T = MCC 2233T = NBRC 110402T).