Halohasta litorea gen. nov. sp. nov., and Halohasta litchfieldiae sp. nov., isolated from the Daliang aquaculture farm, China and from Deep Lake, Antarctica, respectively

Two halophilic archaeal strains, R30T and tADLT, were isolated from an aquaculture farm in Dailing, China, and from Deep Lake, Antarctica, respectively. Both have rod-shaped cells that lyse in distilled water, stain Gram-negative and form red-pigmented colonies. They are neutrophilic, require >120 g/l NaCl and 48–67 g/l MgCl2 for growth but differ in their optimum growth temperatures (30 °C, tADLT vs. 40 °C, R30T). The major polar lipids were typical for members of the Archaea but also included a major glycolipid chromatographically identical to sulfated mannosyl glucosyl diether (S-DGD-1). The 16S rRNA gene sequences of the two strains are 97.4 % identical, show most similarity to genes of the family Halobacteriaceae, and cluster together as a distinct clade in phylogenetic tree reconstructions. The rpoB′ gene similarity between strains R30T and tADLT is 92.9 % and less to other halobacteria. Their DNA G + C contents are 62.4–62.9 mol % but DNA–DNA hybridization gives a relatedness of only 44 %. Based on phenotypic, chemotaxonomic and phylogenetic properties, we describe two new species of a novel genus, represented by strain R30T (= CGMCC 1.10593T = JCM 17270T) and strain tADLT (= JCM 15066T = DSMZ 22187T) for which we propose the names Halohasta litorea gen. nov., sp. nov. and Halohasta litchfieldiae sp. nov., respectively.