Aureimonas flava sp. nov., a novel endophytic bacterium isolated from leaf of Acrostichum aureum.

A Gram-negative, aerobic, coccus-shaped, non-spore-forming bacterium, designated M2BS4Y-1^T, was isolated from a surface-sterilized leaf of Acrostichum aureum collected from Guangxi Zhuang Autonomous Region, China and investigated by a polyphasic approach to determine its taxonomic position. Strain M2BS4Y-1^T grew optimally with 1 % (w/v) NaCl, at 30 °C and at pH 7.0-8.0. Substrate mycelia and aerial mycelia were not formed, and no diffusible pigments were observed on the media tested. Phylogenetic analysis based on its 16S rRNA gene sequence showed that strain M2BS4Y-1^T was most closely related to species of the genus Aureimonas, and shared the highest 16S rRNA gene sequence similarity of 97.79 % to Aureimonas phyllosphaerae DSM 25026^T. The average nucleotide identity (ANI) and in silico DNA-DNA hybridization (DDH) values between strain M2BS4Y-1^T and A.phyllosphaerae DSM 25026^T were 83.7 % and 26.5 %, respectively. The ANI and DDH values were below the recommended thresholds. The DNA G+C content of strain M2BS4Y-1^T was 70.0 mol%. The cell-wall peptidoglycan contained meso-diaminobutyric acid and ubiquinone Q-10 was the respiratory lipoquinone. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, sulfoquinovosyldiacylglycerol, two unknown aminolipids, an unidentified phospholipid and four unidentified lipids, while the major fatty acids were C18 : 1ω7c and C16 : 0. On the basis of phylogenetic, chemotaxonomic and phenotyptic data, strain M2BS4Y-1^T can be characterized to represent a novel species of the genus Aureimonas, for which the name Aureimonas flava sp. nov. is proposed. The type strain is M2BS4Y-1^T (=KCTC 62837^T=CGMCC 1.13747^T).