Aureimonas populi sp. nov., isolated from poplar tree bark

Abstract

Two novel bacterial strains (4M3-2^T and 10-107-7) were isolated from poplar tree bark. The strains were Gram-stain-negative facultative aerobes, and produced short rods that were motile because of polar flagella. A phylogenetic tree was reconstructed based on 16S rRNA gene sequences indicating that the two novel strains are related to species of the genus Aureimonas and Aurantimonas. The two novel strains shared the highest 16S rRNA gene sequence similarities with Aureimonasfrigidaquae CW5 7Y-4^T (97.1 %) and Aureimonasaltamirensis DSM 21988^T (96.6 %)o. The lipids of the novel strain contain diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylcholine and sulfoquinovosyl diacylglycerol. The presence of a distinct glycolipid (sulfoquinovosyl diacylglycerol) is an important chemotaxonomic feature used to distinguish between species of the genera, Aurantimonas and Aureimonas. Additionally, the DNA-DNA hybridization results indicated that the two novel strains represent a novel taxon distinct from Aureimonas frigidaquae. The results of the 16S rRNA gene sequence analysis, as well as the physiological and biochemical characteristics imply that the two novel strains should be assigned to a novel species, with the proposed name Aureimonas populi sp. nov. The type strain is 4M3-2^T (=CFCC 11187^T=KCTC 42087^T).

Keywords: Aureimonas populi; DNA-DNA hybridization; Populus×euramericana; endophytes; new taxa.