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

Abstract

Halophilic archaeal strain TBN37T was isolated from Taibei marine solar saltern near Lianyungang city of Jiangsu province, China. Cells were pleomorphic, flat and contained gas vesicles. Cells of strain TBN37T stained Gram-negative and the colonies were pink-pigmented. The strain was able to grow at 25–50 °C (optimum, 37–40 °C), with 1.4–5.1 M NaCl (optimum, 2.1 M NaCl), with 0–1.0 M MgCl2 (optimum, 0.01 M MgCl2) and at pH 6.0–9.0 (optimum, pH 7.5). Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 8 % (w/v). The major polar lipids of strain TBN37T were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and one major glycolipid chromatographically identical to sulfated mannosyl glucosyl diether (S-DGD-1). On the basis of 16S rRNA gene sequence analysis, strain TBN37T was closely related to Haloplanus natans and Haloplanus vescus, with the same similarity of 97.4 %. The DNA G+C content of strain TBN37T is 64.1 mol%. DNA–DNA hybridization values between strain TBN37T and Haloplanus natans JCM 14081T and between strain TBN37T and Haloplanus vescus RO5-8T were 37.6 % and 42.1 %, respectively. It was concluded that strain TBN37T represents a novel species of the genus Haloplanus, for which the name Haloplanus aerogenes sp. nov. is proposed. The type strain is TBN37T ( = CGMCC 1.10124T  = JCM 16430T).