Two extremely halophilic archaea, strains Al-5T and K-1, were isolated from Lake Tebenquiche (Atacama Saltern, Chile) and Ezzemoul sabkha (Algeria), respectively. Cells of the two strains were short-rod-shaped and Gram-negative; colonies were orange-pigmented. They grew optimally at 37–40 °C and pH 7.0–7.5 in the presence of 25 % (w/v) NaCl. Magnesium was not required. Polar lipid analysis revealed the presence of phosphatidylglycerol and phosphatidylglycerophosphate methyl ester, the absence of phosphatidylglycerosulfate, and the presence of sulfated diglycosyl diether and diether diglycosyl as the sole glycolipids. DNA G+C contents of strains Al-5T and K-1 were 52.4 and 52.9 mol% (T m method), respectively. 16S rRNA gene sequence comparison with database sequences showed that strains Al-5T and K-1 were most closely related to Halomicrobium mukohataei DSM 12286T (similarities of 97.5 and 96.9 %, respectively). DNA–DNA hybridization indicated that strains Al-5T and K-1 were members of a single species. However, DNA–DNA relatedness to Halomicrobium mukohataei was 55.7±2.5 %. A comparative analysis of phenotypic characteristics and DNA–DNA hybridization between the isolates and Halomicrobium mukohataei DSM 12286T supported the conclusion that Al-5T and K-1 represent a novel species within the genus Halomicrobium, for which the name Halomicrobium katesii sp. nov. is proposed. The type strain is Al-5T (=CECT 7257T=DSM 19301T).
Two Gram-negative, rod-shaped, halophilic archaea, designated strains HIS40-3T and HDS3-1, were isolated from anchovy fish sauce (nam-pla) collected from two different locations in Thailand. The two strains were able to grow at 20–60 °C (optimum 37–40 °C), at 1.7–5.1 M NaCl (optimum 2.6–3.4 M NaCl) and at pH 5.5–8.5 (optimum pH 6.0–6.5). Hypotonic treatment with less than 1.7 M NaCl caused cell lysis. The major polar lipids of the isolates were C20C20 and C20C25 derivatives of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate, two glycolipids and one unidentified lipid. The DNA G+C contents were 64.0–65.4 mol%. In addition to phenotypic and chemotaxonomic characteristics, phylogenetic analysis based on 16S rRNA gene sequence similarities showed that strains HIS40-3T and HDS3-1 were related most closely to species of the genus Natrinema. Levels of 16S rRNA gene sequence similarity between strains HIS40-3T and HDS3-1 and the type strains of recognized Natrinema species were 99.1–96.6 %. The two novel strains could be distinguished from recognized Natrinema species on the basis of low levels of DNA–DNA relatedness and differences in whole-cell protein patterns and phenotypic properties. Levels of 16S rRNA gene sequence similarity and DNA–DNA relatedness between the two strains were 99.7 and 77.7 %, respectively, suggesting that they should be classified as representing a single species. Based on these taxonomic data, strains HIS40-3T and HDS3-1 are considered to represent a novel species of the genus Natrinema, for which the name Natrinema gari sp. nov. is proposed. The type strain is HIS40-3T (=BCC 24370T =JCM 14663T =PCU 303T).