Haloplanus salinus sp. nov., an extremely halophilic archaeon from a Chinese marine solar saltern

Abstract

Halophilic archaeal strain YGH66^T was isolated from the Yinggehai marine solar saltern near the Sanya city of Hainan Province, China. Cells were pleomorphic, flat, stained Gram-negative, and produced pink-pigmented colonies. Strain YGH66^T was able to grow at 20–50 °C (optimum 37 °C), at 0.9–4.8 M NaCl (optimum 3.1 M NaCl), at 0.005–1.0 M MgCl₂ (optimum 0.05 M MgCl₂), and at pH 6.0–8.0 (optimum pH 7.0). The cells of strain YGH66^T were lysed in distilled water, and the minimum NaCl concentration that prevented cell lysis was 5 % (w/v). The major polar lipids of the strain were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate, one major glycolipid (GL1) chromatographically identical to sulfated mannosyl glucosyl diether and a minor unidentified lipid (GL2), respectively. On the basis of 16S rRNA gene sequence analysis, strain YGH66^T was closely related to Haloplanus natans JCM 14081^T, Haloplanus aerogenes TBN37^T, and Haloplanus vescus RO5-8^T with the similarities of 98.0, 97.6, and 96.9 %, respectively. The rpoB′ gene similarity between strain YGH66^T and the current three members of Haloplanus were 90.4–92.8 %. The DNA G+C content of strain YGH66^T was 67.2 mol %. The DNA–DNA hybridization values between strain YGH66^T and three members of Haloplanus, H. natans JCM 14081^T, H. aerogenes TBN37^T, H. vescus RO5-8^T were 50, 46 and 39 %, respectively. It was concluded that strain YGH66^T represents a novel species of the genus Haloplanus, for which the name Haloplanus salinus sp. nov. is proposed. The type strain is YGH66^T (=CGMCC 1.12127^T = JCM 18368^T).