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 °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(H₄), MK-7(H₂) 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).

Pseudaminobacter arsenicus sp. nov., an arsenic-resistant bacterium isolated from arsenic-rich aquifers

An arsenic-resistant strain, CB3^T, was isolated from arsenic-rich aquifers at the Jianghan Plain in Hubei, China. Phylogenetic and biochemical analysis suggested that it should represent a new species of the genus Pseudaminobacter in the family Phyllobacteriaceae. The 16S rRNA gene of CB3^T shared the highest sequence similarities to those of the type strains Pseudaminobacter defluvii THI 051^T (97.8 % identity) and Pseudaminobacter salicylatoxidans BN12^T (97.4 %). The DNA-DNA relatedness values of CB3^T with respect to strains belonging to the genus Pseudaminobacter were less than 70 %. The fatty acid profile of CB3^T consisted of C16 : 0, cyclo-C19 : 0ω8c and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) as major components. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidyldimethylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylethanolamine and diphosphatidylglycerol. The DNA G+C content was 61.4 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain CB3^T was distinct from previously described Pseudaminobacter species. Therefore, we propose that strain CB3^T represents a novel species of the genus Pseudaminobacter, Pseudaminobacterarsenicus sp. nov., strain CB3^T (=CCTCC AB2016116^T=KCTC 52625^T) is designated as the type strain.