Halorhabdus amylolytica sp. nov. and Halorhabdus salina sp. nov., isolated from hypersaline environments

Two novel extremely halophilic archaeal strains, designated H27 and FL145 , were isolated from a salt mine and a kelp salt sample, respectively. Cells of both strains were Gram-stain-negative, motile and pleomorphic. The 16S rRNA and ' gene sequence similarities between strains H27 and FL145 were 96.60 and 88.77%. Strains H27 and FL145 were both closely related to WSM-64 , SARL4B and AX-2 , with a 16S rRNA gene sequence similarities of 98.14, 96.34 and 96.27% for strain H27 and 96.42, 95.82 and 96.17% for strain FL145 . The genome-based average nucleotide identity (ANI) values between strains H27 and FL145 , and these three species were 83.93, 79.79 and 79.09% (for strain H27 ), and 78.32, 77.95 and 77.05% (for strain FL145 ), respectively. The ANI value between strains H27 and FL145 was 78.65 %. The digital DNA-DNA hybridization values between strains H27 and FL145 , and these three species were less than 27.40%, which were below the recommended threshold for membership of the same species. The major polar lipids of both strains were found to consist of sulfated diglycosyl diether, triglycosyl diether, phosphatidylglycerol phosphate methyl ester and phosphatidylglycerol. The DNA G+C content was determined from genome to be 62.10 mol% for strain H27 and 61.51 mol% for strain FL145 . Based on phylogenetic, phenotypic, chemotaxonomic and genomic analyses, these two new isolates should be classified as representing two novel species in the genus , with strain H27 (=CGMCC 1.16342 =NBRC 113589 ) as the type strain of a new species for which we propose the name sp. nov., and strain FL145 (=CGMCC 1.13888 =NBRC 114260 ) as the type strain of another new species for which we propose the name sp. nov.