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Halovivax cerinus sp. nov., an extremely halophilic archaeon from a hypersaline lake

2014; Microbiology Society; Volume: 65; Issue: Pt_1 Linguagem: Inglês

10.1099/ijs.0.069757-0

1466-5034

Mohammad Ali Amoozegar, Ali Makhdoumi, Maliheh Mehrshad, Mehrnoosh Rasooli, Seyed Abolhassan Shahzadeh Fazeli, Cathrin Spröer, António Ventosa,

Protist diversity and phylogeny

An extremely halophilic archaeon, strain IC35(T), was isolated from a mud sample of the Aran-Bidgol salt lake in Iran. The novel strain was cream, non-motile, rod-shaped and required at least 2.5 M NaCl, but not MgCl2, for growth. Optimal growth was achieved with 3.4 M NaCl and 0.1 M MgCl2. The optimum pH and temperature for growth were pH 7.0 (grew over a pH range of 6.5-9.0) and 40 °C (grew over a temperature range of 30-50 °C), respectively. Analysis of 16S rRNA gene sequences revealed that strain IC35(T) clustered with species of the genus Halovivax, with sequence similarities of 97.3%, 96.6% and 96.3%, respectively, to Halovivax limisalsi IC38(T), Halovivax asiaticus EJ-46(T) and Halovivax ruber XH-70(T). The rpoB' gene similarities between the novel strain and Halovivax limisalsi IBRC-M 10022(T), Halovivax ruber JCM 13892(T) and Halovivax asiaticus JCM 14624(T) were 90.2 %, 90.2% and 89.9%, respectively. The polar lipid pattern of strain IC35(T) consisted of phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester; six unknown glycolipids and two minor phospholipids were also observed. The only quinone present was MK-8 (II-H2). The G+C content of the genomic DNA was 63.2 mol%. DNA-DNA hybridization studies (29% hybridization with Halovivax limisalsi IBRC-M 10022(T)), as well as biochemical and physiological characterization, allowed strain IC35(T) to be differentiated from other species of the genus Halovivax. A novel species, Halovivax cerinus sp. nov., is therefore proposed to accommodate this strain. The type strain is IC35(T) ( = IBRC-M 10256(T) = KCTC 4050(T)).