A novel halophilic archaeon, NG4T, was isolated from Jilantai salt lake in Inner Mongolia, China. The taxonomy of strain NG4T was studied by polyphasic methods. Strain NG4T grew at pH 5.5–8.5 and at a temperature of 22–55 °C. It was chemo-organotrophic, aerobic and required concentrations of 2.7–5.2 M NaCl and 0.05–0.3 M Mg2+ for growth. Cells were Gram-negative, slender rods. Colonies on agar plates containing 25 % (w/v) total salts were red, elevated and round. According to 16S rRNA gene sequence similarity, strain NG4T was phylogenetically related to Halobacterium salinarum DSM 3754T (98.2 %) and Halobacterium noricense A1T (97.3 %). The DNA G+C content was 64.2 mol%. DNA–DNA relatedness values with Hbt. salinarum DSM 3754T and Hbt. noricense A1T were 47 and 35 %, respectively. The polar lipids of strain NG4T consisted of phosphatidylglycerol, methylated phosphatidylglycerol phosphate, phosphatidylglycerol sulfate, triglycosyl diether, sulfated triglycosyl diether and sulfated tetraglycosyl diether. It was concluded that strain NG4T represents a novel species of the genus Halobacterium, for which the name Halobacterium jilantaiense sp. nov. is proposed. The type strain is NG4T (=CGMCC 1.5337T=JCM 13558T).
Surviving salt fluctuations: stress and recovery in Halobacterium salinarum, an extreme halophilic Archaeon
