Haloparvum Alkalitolerans Sp. Nov., Alkali-Tolerant Haloarchaeon Isolated from Commercial Salt.

A Gram-stain-negative, rod-pleomorphic, aerobic, halophilic archaeon, strain MK62-1(T), was isolated from commercial salt made from seawater in the Philippines. Strain MK62-1(T) was able to grow at 2.1-4.7 M NaCl (with optimum at 2.1-2.6 M NaCl), pH 6.5-9.5 (optimum, pH 7.0-7.5) and 20-55 degrees C (optimum, 45-50 degrees C). Based on the orthologous 168 rRNA gene sequence, the closest relative was Haloparvum sedimenti JCM 30891(T) with 99.2% similarity. The RNA polymerase subunit B' gene sequence also showed the highest similarity (97.4%) to that of Haloparvum sedimenti DYS4(T). The DNA G+C content of MK62-1(T) was 70.1 mol%, while that of Haloparvum sedimenti JCM 30891(T) was 69.5 mol% by the HPLC method. The levels of DNA DNA relatedness between MK62-1(T) and Haloparvum sedimenti JCM 30891(T) were 60.6 and 60.8% (reciprocally). The major polar lipids of the isolate were C20C20 archaeol derivatives of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and phosphatidylglycerol sulfate. Based on the phenotypic and phylogenetic analyses, it is proposed that the isolate represents species within the genus Haloparvum, for which the name Haloparvum alkalitolerans sp. nov. is proposed. The type strain is MK62-1(T) (=JCM 30442(T) =KCTC 4214(T)).