Halorubrum depositum sp. nov., a Novel Halophilic Archaeon Isolated from a Salt Deposit.

A non-motile, pleomorphic rod-shaped or oval, red-pigmented (nearly scarlet), extremely halophilic archaeon, strain Y78, was isolated from a salt deposit of Yunnan salt mine, China. Analysis of the 16S rRNA gene sequence showed that it was phylogenetically related to species of the genus Halorubrum, with a close relationship to Halorubrum rutilum YJ-18-S1 (98.6%), Halorubrum yunnanense Q85 (98.3%), and Halorubrum lipolyticum 9-3 (98.1%). The temperature, NaCl, and pH ranges for growth were 25-50 °C, 12-30% (w/v), and 6.5-9.0, respectively. Mg was required for growth. The polar lipids of strain Y78 were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate, and a sulfated diglycosyl diether. The DNA G+C content was 66.6 mol%. DNA-DNA hybridization values between strain Y78 and two closely related species of the genus Halorubrum were far below 70%. Based on the data presented in this study, strain Y78 represents a novel species for which the name Halorubrum depositum sp. nov. is proposed; the type strain is Y78 (= CGMCC 1.15456 = JCM 31272).