Description of Halegenticoccus soli gen. nov., sp. nov., a halophilic archaeon isolated from a soil sample of Ebi lake.

Abstract

Two extreme halophilic archaeal strains, SYSUA9-0T and SYSUA9-1, were isolated from Ebi lake of Xinjiang, China. The colonies were Gram-negative, coccoid, and non-motile. Strains were aerobic and grew at 25-50°C (optimum at 37°C), in the presence of 10-35% (w/v) NaCl (optimum at 20-22%), and pH 6.0-8.0 (optimum at 7.0). The 16S rRNA gene sequence result revealed that the two strains were closely related to Haloprofundus marisrubri SB9T (92.7% similarity). The DNA-DNA hybridization value (97% ± 1%) suggested that SYSUA9-0T and SYSUA9-1 were similar; however, their sequence similarities with other archaeal members suggested that they were novel candidates. The genomic G + C content of SYSUA9-0T was 66.9%. The average nucleotide identity value between SYSU A9-0T and Haloprofundus marisrubri SB9T was 69.1%, which was far below the cutoff value (95-96%) proposed to define the species boundary. The polar lipids were phosphatidylglycerol (PG), phosphatidylglycerolphosphate methylester (PGP-Me), sulfated mannosyl glucosyl diether, mannosyl glucosyldiether, and four unidentified glycolipids. Phenotypic, chemotaxonomic and comparative genome analysis suggested that SYSU A9-0T and SYSU A9-1 represent a novel species of a new genus within the family Haloferacaceae, for which the name Halegenticoccus soli gen. nov., sp. nov., is proposed. The type strain is SYAUA9-0T (= KCTC4241T = CGMCC 1.15765T).