Fifteen strains of red-pigmented, strictly aerobic, coccoid, extremely halophilic archaea were isolated from fish sauce (nam-pla) produced in Thailand. They grew optimally at 37 °C, pH 6–8 and in the presence of 20–30 % (w/v) NaCl. The DNA G+C contents of the isolates were 60.0–61.8 mol%. They had MK-8(H2) as a major menaquinone component and C20C20 and C20C25 derivatives of phosphatidylglycerol, phosphatidylglycerol methylphosphate and a sulfated glycolipid, S-DGA-1, as major polar lipid components. 16S rRNA gene sequence comparisons revealed that a representative strain, HDB5-2T, was affiliated with Halococcus dombrowskii JCM 12289T, Halococcus qingdaonensis JCM 13587T and Halococcus morrhuae JCM 8876T (levels of similarity of 98.2–98.7 %). Based on data from DNA–DNA hybridization experiments, the 15 strains represented a single species, showing hybridization values of >78.9 % to representative strain HDB5-2T, but were unrelated to either Halococcus dombrowskii JCM 12289T or Halococcus morrhuae JCM 8876T, with levels of relatedness of <50 %. Moreover, a comparison of phenotypic properties discriminated these new isolates from recognized species of the genus Halococcus. The 15 strains are thus considered to represent a novel species of the genus Halococcus, for which the name Halococcus thailandensis sp. nov. is proposed. The type strain is HDB5-2T (=BCC 20213T =JCM 13552T =PCU 278T).
An extremely halophilic archaeon, strain Fa-1T, was isolated from a marine solar saltern in Fujian, China. Strain Fa-1T required Mg2+ and at least 2.0 M NaCl for growth. It was able to grow at pH 6.5–9.0 (optimally at pH 7.0–7.5) and at 20–55 °C (optimally at 37–42 °C). The major polar lipids of strain Fa-1T were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and a sulfated diglycosyl diether. On the basis of a 16S rRNA gene sequence analysis, strain Fa-1T was closely related to nine species of the genus Halorubrum, showing sequence similarities of 97.4–98.4 %. The G+C content of the DNA of strain Fa-1T is 64.9 mol% (T m). DNA–DNA hybridization values between strain Fa-1T and the most closely related members of the genus Halorubrum were below 51 %. On the basis of the data from this study, strain Fa-1T represents a novel species of the genus Halorubrum, for which the name Halorubrum litoreum sp. nov. is proposed. The type strain is Fa-1T (=CGMCC 1.5336T =JCM 13561T).
A novel, extremely halophilic archaeon B3T was isolated from shrimp-salted seafood. Its morphology, physiology, biochemical features and 16S rRNA gene sequence were characterized. Strain B3T is non-motile, Gram-variable, requires at least 10 % (w/v) NaCl for growth and grows in the ranges of 21–50 °C and pH 6.5–9.0. The DNA G+C content of strain B3T was 63.2 mol%. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain B3T belonged to the genus Halalkalicoccus and was phylogenetically closely related to the type strain Halalkalicoccus tibetensis (98.64 %). However, DNA–DNA hybridization experiments showed 7.0 % relatedness between strain B3T and a strain of a reference species of the genus Halalkalicoccus. Combined analysis of 16S rRNA gene sequences, DNA–DNA relatedness data, physiological and biochemical tests indicated that the genotypic and phenotypic characteristics differentiate strain B3T from other Halalkalicoccus species. On the basis of the evidence presented in this report, strain B3T represents a novel species of the genus Halalkalicoccus, for which the name Halalkalicoccus jeotgali. sp. nov. is proposed. The type strain is B3T (=KCTC 4019T=DSM 18796T=JCM 14584T=CECT 7217T).