sp. nov. and sp. nov., isolated from saline soil and a salt mine.

A polyphasic study was undertaken to determine the taxonomic position of two halophilic archaeal strains, TH32 and YPL4, isolated from saline soil and a salt mine in PR China, respectively. Strains TH32 and YPL4 both have two dissimilar 16S rRNA genes. The two strains exhibited sequence similarities of 91.5-95.5 % for 16S rRNA genes and 90.9 % for the gene. Sequence similarities of 16S rRNA genes and the gene between the two strains and the current four members of were 90.6-97.4 % and 91.4-93.5 %, respectively. Phylogenetic analysis revealed that the two strains formed different branches separating them from the current members. Several phenotypic characteristics differentiate strains TH32 and YPL4 from current members. The polar lipids of the two strains are phosphatidic acid, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and four glycolipids. Two of the glycolipids are chromatographically identical to disulfated mannosyl glucosyl diether and sulfated mannosyl glucosyl diether, respectively, and the remaining two glycolipids are unidentified. The average nucleotide identity (ANI) and DNA-DNA hybridization (DDH) values between the two strains and the current members of (ANI 80.4-89.2 % and DDH 24.0-41.8 %) were much lower than the threshold values proposed as a species boundary, suggesting that the two strains represent novel species of . The values between the two strains (ANI 81.3 % and DDH 24.9 %) were also much lower than the recommended threshold values, which revealed that the two strains represent two genomically different species of . These results showed that strains TH32 (=CGMCC 1.15190=JCM 30840) and YPL4 (=CGMCC 1.15329=JCM 31108) represent two novel species of , for which the names sp. nov. and sp. nov. are proposed.