Natrialba swarupiae sp. nov., a halophilic archaeon isolated from a hypersaline lake in India

A haloarchaeal strain (ESP3B_9 T ) was isolated from the salt pan of Sambhar salt lake, Rajasthan, India. Cells were coccoid, non-motile, Gram-stain-negative and formed reddish-pink pigmented colonies. The strain was aerobic, able to grow at 35–55 °C (optimum, 40 °C), in 20–35 % (25 %) NaCl and pH 8–10 (pH 9). Mg 2+ not required for growth. The cells were lysed in distilled water and the minimum NaCl concentration that prevented cell lysis was 5 % w/v. The 16S rRNA gene sequence similarities between strain ESP3B_9 T and Natrialba hulunbeirensis JCM 10989 T and Natrialba magadii ATCC 43099 T were 96.53 and 96.25 % respectively. The similarities of the RNA polymerase subunit B gene between strain ESP3B_9 T and N. hulunbeirensis JCM 10989 T and N. magadii ATCC 43099 T were 84.47 and 84.9 % respectively. Genome sequencing revealed a genome size of 4.20 Mbp with DNA G+C content of 62.5 mol%. The major polar lipids were phosphotidylglycerol and phosphatidylglycerol phosphate methyl esters with minor amounts of unidentified lipids. The results of polyphasic analysis determined that strain ESP3B_9 T represents a novel species of the genus Natrialba , for which the name Natrialba swarupiae sp. nov. is proposed. The type strain is ESP3B_9 T (MCC 3419 T =JCM 33002 T =KCTC 4279 T =CGMCC 1.16737 T ).