Mongoliitalea lutea gen. nov., sp. nov., an alkaliphilic, halotolerant bacterium isolated from a haloalkaline lake.

Two bacterial isolates from the surface water of a haloalkaline lake on the Mongolia Plateau, strains MIM18(T) and MIM19, were characterized; their morphological, physiological and chemotaxonomic characters, and phylogenetic position based on 16S rRNA gene sequences, were determined. The two strains were alkaliphilic, halotolerant, non-motile, aerobic, Gram-negative, orange-red, rod-shaped and oxidase-positive. Growth was observed in 0-5.5% (w/v) NaCl, with optimum growth at 1%. The temperature range for growth was 0-41 °C, with good growth at 28-37 °C and optimum growth at 30-33 °C. The DNA G+C content was 39.8-41.2 mol%. The strains contained menaquinone MK-7 as the major respiratory quinone and phosphatidylcholine, phosphatidylglycerol and phosphatidylethanolamine as the major polar lipids. Predominant cellular fatty acids were iso-C(15:0) (28.1-29.3%), iso-C(17:0) 3-OH (14.6-18.8%), C(15:1)ω6c (5.3-8.6%), C(14:0) 2-OH and/or iso-C(15:0) 2-OH (5.4-6.1%), and iso-C(17:1)ω9c and/or C(16:0) 10-methyl (5.0-6.8%). 16S rRNA gene sequence analysis showed that Belliella and Nitritalea of the family Cyclobacteriaceae were the closest related species with sequence similarities of 91.7-92.3% and 88.2%, respectively, with strains of these genera; other members of the Cyclobacteriaceae had sequence similarities lower than 88%. Phylogenetic analysis indicated that the strains formed a deep-rooted lineage distinct from the clades represented by the genera Belliella, Nitritalea, Indibacter, Aquiflexum, Echinicola, Litoribacter, Cyclobacterium and Algoriphagus. Based on the phenotypic and phylogenetic characteristics mentioned above, the two strains are representatives of a single novel species in a new genus; the name Mongoliitalea lutea gen. nov., sp. nov. is proposed, with MIM18(T) (=ACCC 05421(T)=KCTC 23224(T)) as the type strain.