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

Abstract

Halophilic archaeal strain TBN37(T) 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 TBN37(T) 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 MgCl(2) (optimum, 0.01 M MgCl(2)) 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 TBN37(T) 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 TBN37(T) was closely related to Haloplanus natans and Haloplanus vescus, with the same similarity of 97.4 %. The DNA G+C content of strain TBN37(T) is 64.1 mol%. DNA-DNA hybridization values between strain TBN37(T) and Haloplanus natans JCM 14081(T) and between strain TBN37(T) and Haloplanus vescus RO5-8(T) were 37.6 % and 42.1 %, respectively. It was concluded that strain TBN37(T) represents a novel species of the genus Haloplanus, for which the name Haloplanus aerogenes sp. nov. is proposed. The type strain is TBN37(T) ( = CGMCC 1.10124(T) = JCM 16430(T)).