Very similar strains of Halococcus salifodinae are found in geographicallyseparated Permo-Triassic salt deposits

The authors have previously isolated a novel extremely halophilic archaeon, Halococcus salifodinae Blp, from Austrian rock salt deposited about 250 mi llion years ago, In this study they compared strain Blp with two other halo cocci isolated independently from geographically distant salt deposits of s imilar age, and with two recent isolates (N1 and H2) from the same site as strain Blp, Strain BG2/2 was from a salt mine in Germany and strain Br3 fro m a halite deposit in England; both resembled Hc. salifodinae Blp in cellul ar and colonial morphology. Strains Blp, BG2/2 and Br3 had identical 16S rR NA sequences, very similar whole-cell protein patterns, which were differen t from those of other halococci, similar G+C contents and identical sequenc es in a 108-base insertion in their 5S rRNA gene, Other similarities includ ed composition and relative abundances of polar lipids, antibiotic suscepti bility, enzymic activities and Fourier-transform infrared spectra. Strains N1 and H2 showed similar morphology, whole-cell protein patterns and bioche mical characteristics as strains Blp, Br3 and BG2/2, Their partial 16S rRNA sequences (682 and 641 bases, respectively) were indistinguishable from th ose of strains Blp, Br3 and BG2/2, Therefore strains N1 and H2 can be consi dered as reisolates of Hc. salifodinae which were obtained 8 years after th e first samples were taken from that mine, The results presented suggest th at viable halophilic archaea, which belong to the same species, occur in wi dely separated evaporite locations of similar geological age, and support t he notion that these halophilic isolates from subterranean salt deposits ma y be the remnants of populations which inhabited ancient hypersaline seas.