Rahnella aceris sp. nov., isolated from sap drawn from Acer pictum

A Gram-reaction-negative, facultatively anaerobic bacterium, designated SAP-19^T, was isolated from sap extracted from Acer pictum in Mt. Halla in Jeju, Republic of Korea and its taxonomic statue was investigated by a polyphasic approach including genome- and 16S rRNA gene-based phylogenetic analyses. Cells were motile, short rods and showed growth at 20-30 °C, pH 4-9 and 0-6% (w/v) NaCl. The whole genome- and 16S rRNA gene-based phylogenetic analyses exhibited that strain SAP-19^T belongs to the genus Rahnella and forms a tight cluster with Rahnella aquatilis. The isolate shared average nucleotide identity of 92.7% and 16S rRNA gene sequence similarity of 99.6% with the type strain of Rahnella aquatilis. The polar lipids contained phosphatidylethanolamine, an unidentified aminophospholipid and an unidentified lipid. The major isoprenoid quinone was Q-8. The predominant fatty acids were C_16:0 and C_17:0cyclo. The G + C content of the genome was 52.3%. The low average nucleotide identity (92.7%) and digital DNA relatedness (48.6%) values between the isolate and the most closely related strain showed that the isolate can be considered a different genospecies. On the basis of combined data obtained in this study, strain SAP-19^T (= KACC 21744^T = NBRC 114407^T) represents a novel species of the genus Rahnella, for which the name Rahnella aceris sp. nov. is proposed.

Keywords: Acer pictum; Rahnella aceris; Tree sap; Yersiniaceae.