Genome-Based Classification of 'Haloarcula aidinensis' and Description of Three Novel Halophilic Archaea Isolated from an Inland Saline Lake, Coastal Saline Soil, and a Marine Solar Saltern.

'Haloarcula aidinensis' was described by a pioneer Chinese scientist focused on halophilic archaea thirty years ago, and the type strain of 'Haloarcula aidinensis' was recently classified based on phylogenetic, phylogenomic, and comparative genomic analyses. Other three novel halophilic archaeal strains, CK38^T, DT43^T, and SYNS111^T, isolated from diverse saline environments in China, were simultaneously subjected to polyphasic classification. 'Haloarcula aidinensis' A₅ was found to be related to Haloarcula amylolytica, while strains CK38^T, DT43^T, and SYNS111^T represented three novel species of Haloarcula based on phylogenetic, phylogenomic, and comparative genomic analyses. These strains can be distinguished from other species within the genus Haloarcula based on multiple phenotypic characteristics. The major phospholipids, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, and phosphatidylglycerol sulfate can be detected in these strains, while the glycolipid profiles of these strains are diverse. Strains A₅ and DT43^T contained glucosyl mannosyl glucosyl diether and a diglycosyl diether, while other strains CK38^T and SYNS111^T had sulfated mannosyl glucosyl diether and mannosyl glucosyl diether. Thus, strain A₅ should be a reference strain of Har. amylolytica and three novel species of Haloarcula, Haloarcula sediminis sp. nov., Haloarcula brevis sp. nov., and Haloarcula regularis sp. nov. are proposed to accommodate strains CK38^T (= CGMCC 1.62732^T = JCM 36675^T), DT43^T (= CGMCC 1.18924^T = JCM 36146^T), and SYNS111^T (= CGMCC 1.62601^T = JCM 36149^T).