Nesterenkonia haasae sp. nov., an alkaliphilic actinobacterium isolated from a degraded pasture in Songnen Plain

An alkaliphilic actinobacterial strain, designated Hz 6-5(T), was isolated from saline-alkaline soil from Songnen Plain in north-eastern China. The isolate formed light yellow-colored colonies and its cells were Gram-staining positive, non-motile, and non-spore-forming short rods. The strain was aerobic with optimal growth at 33 degrees C, pH 9.0, and in the presence of 0.5% (w/v) NaCl or 3% (w/v) KCl. It was catalase-positive and oxidase-negative. The isolate had highest 16S rRNA gene sequence similarities to the type strains of the species Nesternkonia natronophila M8(T) (98.2%), N. salmonea GY074(T) (98.1%), and N. sphaerica GY239(T) (97.4%), and the isolate formed a subclade with the type strains of these species in the neighbor-joining tree based on the 16S rRNA gene sequences. The phylogenetic tree based on the phylogenomic analysis also showed the same results. The DNA-DNA relatedness (DDH) values of isolate Hz 6-5(T) with N. natronophila M8(T), N. halophila DSM 16378(T), and N. halobia CGMCC 1.2323(T) were 21.2%, 36.5%, and 32.0%, respectively. The characteristic diamino acid of strain Hz 6-5(T) was found to be lysine. The respiratory quinones were MK-9, MK-8, MK-7(H-4), MK-7(H-2) and MK-7 and the major cellular fatty acids (> 10%) were anteiso-C-15:0, anteiso-C-17:0 and iso-C-16:0. The polar lipids detected for strain Hz 6-5(T) were diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol, an unidentified glycolipid, and two unidentified phospholipids. The DNA G + C content of isolate Hz 6-5(T) was 60.8%. Based on the results of phylogenetic analysis supported by morphological, physiological, chemotaxonomic, and other differentiating phenotypic evidence, strain Hz 6-5(T) is considered to represent a novel species of the genus Nesterenkonia, for which the name Nesterenkonia haasae sp. nov. is proposed. The type strain is Hz 6-5(T) (=CPCC 205100(T)=NBRC 113521(T)).

Automated summary

An alkaliphilic actinobacterial strain, Hz 6-5(T), isolated from saline-alkaline soil in northeastern China, showed optimal growth conditions at 33 degrees C, pH 9.0, and in the presence of 0.5% NaCl or 3% KCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed the strain to be a novel species of the genus Nesterenkonia.