Haloarcula salaria sp. nov. and Haloarcula tradensis sp. nov., isolated from salt in Thai fish sauce.

Two red-pigmented, strictly aerobic, pleomorphic rod-shaped and extremely halophilic archaea, designated strains HST01-2R(T) and HST03(T), were isolated from salt in a fish sauce sample from Thailand. The novel strains grew optimally at 37 °C, pH 7.0, and in the presence of 20-25 % (w/v) NaCl. The DNA G+C contents of the isolates were 61.6-62.2 mol%. Phylogenetic analysis based on a comparison of 16S rRNA gene sequences revealed that strains HST01-2R(T) and HST03(T) were placed in the radiation of species of the genus Haloarcula. The chemotaxonomic properties of the two strains, i.e. the presence of MK-8 and MK-8(H(2)) as the major menaquinone components and C(20)C(20) derivatives of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and a triglycosyl diether as major polar lipids, supported the assignment of the two strains to the genus Haloarcula. Nevertheless, several phenotypic features and the low DNA-DNA relatedness between the two strains and related species of the genus Haloarcula (13.4-46.9 %) enabled the strains to be distinguished from each other and from recognized species. Therefore, strains HST01-2R(T) and HST03(T) represent two novel species in the genus Haloarcula, for which the names Haloarcula salaria sp. nov. and Haloarcula tradensis sp. nov. are proposed, respectively. The type strains are HST01-2R(T) (=BCC 40029(T)=JCM 15759(T)=PCU 313(T)) and HST03(T) (=BCC 40030(T)=JCM 15760(T)=PCU 314(T)).