Halobellus marinus sp. nov., Halobellus ordinarius sp. nov., Halobaculum rarum sp. nov., and Halorarum halobium sp. nov., halophilic archaea isolated from marine solar salt and a saline lake

Four halophilic archaeal strains were isolated from sea salt and a saline lake in China. Based on phylogenetic and phylogenomic analyses, the four strains are related to the genera of Halobellus, Halobaculum, and Halorarum within the family Haloferacaceae. The four strains possess genes responsible for carotenoid synthesis, maintenance of a high internal salt concentration, as well as diverse enzymes with biotechnological potential. The average nucleotide identity (ANI), average amino acid identity (AAI), and digital DNA-DNA hybridization (dDDH) values among these four strains and their related species were lower than the established thresholds proposed for species demarcation. Strains DFY28T, ZY16T, QDC11T, and XH14T were distinguished from related species based on a variety of phenotypic characteristics. The major polar lipids of these four strains were similar to those of respective relatives within the genera Halobellus, Halobaculum, and Halorarum. The phenotypic, phylogenetic, and genome-based analyses suggest that strains DFY28T (= CGMCC 1.17470T = JCM 34310T), ZY16T (= CGMCC 1.17476T = JCM 34311T), QDC11T (= MCCC 4K00127T = KCTC 4308T), and XH14T (= CGMCC 1.17028T = JCM 34145T) represent four novel species of the genera Halobellus, Halobaculum and Halorarum, for which the names Halobellus marinus sp. nov., Halobellus ordinarius sp. nov., Halobaculum rarum sp. nov., and Halorarum halobium sp. nov. are proposed.