Haloalkaliphilic denitrifiers Halomonas nitritofilus from soda lakes Buryatiya

The directed screening of denitrifying gram-negative bacteria, phenotypically similar to bacteria of the genus Halomonas is carried out. Isolates differ from the "classical" Halomonas in pH range for growth (7.0 - 11.0) and rates of denitrification exceeding the known values is several times greater, and in resistance to high concentrations of sodium nitrite and ability to reduce very low starting concentrations of nitrite ion in alkaline conditions. Phylogenetic analysis of 16S rRNA gene obtained isolates identified them as belonging to an amorphous group III phylogenetic ("ungrouped" Halomonas) with the level of similarity of 93-98%. The isolates formed two compact clusters within this group with high levels of similarity of 97-100% and similar phenotypic properties. Nominees for a new species of 'Halomonas nitritophilus' have been proposed in each cluster.