Haloplanus rallus sp. nov., a halophilic archaeon isolated from crude solar salt

Abstract

A halophilic archaeon, strain MBLA0036^T, was isolated from Sorae solar saltern near Incheon, Republic of Korea. Strain MBLA0036^T had three 16S rRNA genes: rrnA, rrnB and rrnC. The 16S rRNA gene sequence similarities between strain MBLA0036^T (based on the rrnA gene) and Haloplanus ruber R35^T and Haloplanus litoreus GX21^T were 98.0 and 97.3 %, respectively. The similarities of the RNA polymerase subunit B' gene between strain MBLA0036^T and H. ruber R35^T and H. litoreus GX21^T were 94.0 and 92.1 %, respectively. Cells of strain MBLA0036^T were Gram-stain-negative, motile, red-pigmented, pleomorphic, flat and contained gas vesicles. Strain MBLA0036^T grew at 15‒55 °C (optimum, 37 °C), in 10‒30 % (w/v) NaCl (15 %, w/v) with 0‒0.5 M MgSO4.7H2O (0.2 M) and at pH 6.0-9.0 (pH 7.0). The cells lysed in distilled water and the minimum NaCl concentration that prevented cell lysis was 5 % (w/v). Major polar lipids of strain MBLA0036^T were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and a glycolipid that was chromatographically identical to sulfated mannosyl glucosyl diether. The major isoprenoid quinone was menaquinone-8. The genomic DNA G+C content was 65.5 mol%. DNA-DNA hybridization values between strain MBLA0036^T and H. ruber JCM 17271^T and H. litoreus JCM 17092^T were 35±3 and 18±1 %, respectively. Therefore, strain MBLA0036^T is described a novel species of the Haloplanus, for which we propose the name Haloplanusrallus sp. nov. The type strain is MBLA0036^T (=KCTC 4239^T=JCM 31425^T).

Keywords: Haloarchaea; Haloplanus rallus; polyphasic taxonomy; solar salt.