Abstract
A novel extremely halophilic archaeon, strain XF10(T), was isolated from a salt lake in China. This organism was neutrophilic, non-motile and pleomorphic, and was rod, coccus or irregularly shaped. It required at least 1.5 M NaCl for growth and grew in a wide range of MgCl(2) concentrations (0.005--0.5 M). Lipid extract of whole cells contained two glycolipids with the same chromatographic properties as two unidentified glycolipids found in the two described Natrinema species, Natrinema pellirubrum and Natrinema pallidum. Phylogenetic analysis based on 16S rDNA sequence comparison revealed that strain XF10(T) clustered with the two described Natrinema species and several other strains (strains T5.7, GSL-11 and Haloterrigena turkmenica JCM 9743) with more than 98.1% sequence similarities, suggesting that strain XF10(T) belongs to the genus Natrinema. Comparative analysis of phenotypic properties and DNA--DNA hybridization between strain XF10(T) and the Natrinema species supported the conclusion that strain XF10(T) is a novel species within the genus Natrinema. The name Natrinema versiforme sp. nov. is proposed for this strain. The type strain is XF10(T) (=JCM 10478(T)=AS 1.2365(T)=ANMR 0149(T)).