Haloarcula mannanilytica sp. nov., a galactomannan-degrading haloarchaeon isolated from commercial salt

A mannan-degrading halophilic archaeal strain, MD130-1(T), was isolated from a commercial salt sample. Cells were motile, rod-shaped, and stained Gram-negative. Colonies were pink pigmented. Strain MD130-1(T) was able to grow at 1.5-4.6 M NaCl (optimum, 3.6 M) at pH 6.0-8.0 (optimum, pH 7.0) and at 25-50 degrees C (optimum, 40 degrees C). The DNA G+C content was 62.1 mol% (genome). The orthologous 16S rRNA gene sequence showed the highest similarity (99.4 %) to those of Haloarcula japonica JCM 7785(T) and Haloarcula hispanica JCM 8911(T). The values of genome relatedness between strain MD130-1(T) and Haloarcula species were 84.33-85.96 % in ANIb and 30.4-32.9% using GGDC formula 2. The polar lipids of strain MD130-1(T) were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and triglycosyl diether-2. Based on the results of phenotypic and phylogenetic analyses, the strain represents a new species of the genus Haloarcula, for which the name Haloarcula mannanilytica sp. nov. is proposed. The type strain is MD130-1(T) (=JCM 33835(T)=KCTC 4287(T)) isolated from commercial salt made in Ishikawa prefecture, Japan.