HALOBACULUM GOMORRENSE GEN-NOV, SP-NOV, A NOVEL EXTREMELY HALOPHILIC ARCHAEON FROM THE DEAD-SEA

A novel extremely halophilic archaeon was isolated from the Dead Sea, This isolate is rod shaped and, like Halobacterium sodomense, requires a relatively low level of sodium ions for growth and a very high leve l of magnesium; optimal growth occurs in the presence of 0.6 to 1.0 M Mg2+, The new strain resembles members of the Halobacterium saccharovo rum-Halobacterium sodomense-Halobacterium trapanicum group in many phy siological properties, However, the polar lipid composition of this or ganism is characteristic of representatives of the genus Haloferax; a sulfated diglycosyl diether is present, and the glycerol diether analo g of phosphatidylglycerosulfate is absent, The G+C content of the DNA is 70 mol%. We found that on the basis of 16S rRNA sequence data our n ew isolate occupies a position intermediate between the position of th e Halobacterium saccharovorum group and the position of the genus Halo ferax and is sufficiently different from the previously described memb ers of the Halobacteriaceae to justify classification in a new species and a new genus, We propose the name Halobaculum gomorrense gen. nov. , sp, nov, for this organism; the type strain is strain DSM 9297.