Halomicrococcus gelatinilyticus sp. nov. and Halosimplex aquaticum sp. nov., halophilic archaea isolated from saline soil and an inland solar saltern

Two extremely halophilic archaeal strains, GSLN9 T and XZYJT29 T , were isolated from the saline soil in different regions of western China. Both strains GSLN9 T and XZYJT29 T have two 16S rRNA genes with similarities of 95.1 and 94.8 %, respectively. Strain GSLN9 T was mostly related to the genus Halomicrococcus based on 16S rRNA (showing 91.0–96.0 % identities) and rpoB′ genes (showing 92.0 % identity). Strain XZYJT29 T showed 92.1–97.6 % (16S rRNA gene) and 91.4–93.1 % ( rpoB′ gene) sequence similarities to its relatives in the genus Halosimplex , respectively. The polar lipid profile of strain GSLN9 T included phosphatidic acid (PA), phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), phosphatidylglycerol sulphate (PGS), sulphated mannosyl glucosyl diether (S-DGD-1) and sulphated galactosyl mannosyl glucosyl diether (S-TGD-1), mostly similar to that of Halomicrococcus hydrotolerans H22 T . PA, PG, PGP-Me, S-DGD-1 (S-DGD-PA), S 2 -DGD, S-TGD-1 and an unidentified glycolipid were detected in strain XZYJT29 T ; this polar lipid composition is similar to those of members of the genus Halosimplex . The average nucleotide identity, digital DNA–DNA hybridization and average amino acid identity values between these two strains and their relatives of the genera Halomicrococcus and Halosimplex were no more than 82, 27 and 80 %, respectively, much lower than the thresholds for species demarcation. Other phenotypic characterization results indicated that strains GSLN9 T and XZYJT29 T can be differentiated from the current species of the genera Halomicrococcus and Halosimplex , respectively. These results revealed that strains GSLN9 T (=CGMCC 1.15215 T =JCM 30842 T ) and XZYJT29 T (=CGMCC 1.15828 T =JCM 31853 T ) represent novel species of Halomicrococcus and Halosimplex , for which the names Halomicrococcus gelatinilyticus sp. nov. and Halosimplex aquaticum sp. nov. are proposed.