Natronobacterium texcoconense sp. nov., a haloalkaliphilic archaeon isolated from soil of a former lake

A novel haloalkaliphilic archaeon, strain B23T was isolated from the former lake Texcoco in Mexico. The strain was Gram-stain-negative, the cells coccoid to ovoid rods, red pigmented and aerobic. Strain B23T grew in 1.7–4.3 M NaCl, at pH 6.5–9.5 and at 25–45 °C with optimal growth at 2.6–3.4 M NaCl, pH 7.5–8.5 and 37 °C. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain B23T was most closely related to Natronobacterium gregoryi SP2T with 97.3 % sequence similarity. The polar lipids of strain B23T were phosphatidylglycerol and several unidentified phospholipids. The G+C content of the DNA of the strain was 62.5 mol%. Levels of DNA–DNA relatedness between strain B23T and Natronobacterium gregoryi DSM 3393T was 32.3 %. The name Natronobacterium texcoconense sp. nov. is proposed. The type strain is B23T ( = CECT 8068T = JCM 17655T).