Halobellus rufus sp. nov., an extremely halophilic archaeon isolated from non-purified solar salt

Abstract

A halophilic archaeon, designed strain CBA1103(T), was isolated from non-purified solar salt. The cells of strain CBA1103(T) were observed to be Gram-stain negative and pleomorphic, and the colonies appear red. Strain CBA1103(T) was observed to grow between 20 and 55°C (optimum 37°C), and in NaCl concentrations of 10-30% (w/v) (optimum 15%) with 0-0.5M MgSO4·7H2O (optimum 0.1M) and at pH 6.0-9.0 (optimum pH 7.0). Additionally, the cells lyse in distilled water. The major polar lipids of strain CBA1103(T) are phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and two glycolipids chromatographically identical to sulfated mannosyl glucosyl diether and manosyl glucosyl diether. Strain CBA1103(T) is shown to belong to the Halobellus genus and exhibits similarity to related taxa; the 16S rRNA gene sequence similarity between strain CBA1103(T) and Halobellus rarus 18362(T), Hbs. limi 16811(T), Hbs. litoreus JCM 17118(T), Hbs. inordinatus YC20(T), Hbs. clavatus TNN18(T) and Hbs. salinus CSW2.24.4(T) is 97.3, 96.5, 96.5, 94.5, 94.5 and 93.7%, respectively. The RNA polymerase subunit B gene sequence of strain CBA1103(T) shows 93.7% similarity with the sequence of Hbs. litoreus JCM 17118(T); the similarity is lower with sequences from the type strains of other species of Halobellus. The genomic DNA G+C content of strain CBA1103(T) was determined to be 67.0mol% a value which is in the range of the genomic DNA G+C content of members of the genus Halobellus (61.5-69.2mol%). These results suggest that strain CBA1103(T) should be considered to represent a new taxon for which the name Halobellus rufus sp. nov. is proposed, with the type strain CBA1103(T) (=CECT 8423(T) =JCM 19434(T)).