Haloarchaeobius amylolyticus sp. nov., isolated from a marine solar saltern

Halophilic archaeal strain XD48(T) was isolated from a Chinese marine solar saltern. Cells were pleomorphic, stained Gram-negative and formed red-pigmented colonies on solid media. Strain XD48(T) was found to be able to grow at 25-50 °C (optimum 37 °C), at 0.9-4.8 M NaCl (optimum 3.1 M NaCl), at 0-1.0 M MgCl2 (optimum 0.3 MgCl2) and at pH 5.0-9.5 (optimum pH 6.5). The cells lysed in distilled water, and the minimal NaCl concentration to prevent cell lysis was found to be 5% (w/v). The major polar lipids of the strain were phosphatidic acid (PA), phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), phosphatidylglycerol sulfate (PGS), sulfated galactosyl mannosyl glucosyl diether (S-TGD-1), sulfated mannosyl glucosyl diether (S-DGD-1) and six unknown glycolipids. The 16S rRNA gene and rpoB' gene of strain XD48(T) were phylogenetically related to the corresponding genes of Haloarchaeobius members (92.4-93.9 and 89.6-90.5% similarities, respectively). The DNA G + C content of strain XD48(T) was determined to be 65.3 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain XD48(T) (=CGMCC 1.12230(T) = JCM 18642(T)) represents a new species of Haloarchaeobius, for which the name Haloarchaeobius amylolyticus sp. nov. is proposed.