Description of Paracoccus endophyticus sp. nov., isolated from Gastrodia elata Blume

Abstract

A Gram-stain-negative, strictly aerobic, non-motile strain, SYSUP0003^T, was isolated from tubers of Gastrodia elata Blume. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SYSUP0003^T belonged to the genus Paracoccus, with the highest sequence similarity to the type strain of Paracoccus sediminis (97.5 %). Strain SYSUP0003^T grew at pH 6.0-8.0 and 4-30 °C with optimum growth at pH 7.0 and 28 °C. Strain SYSUP0003^T could tolerate up to 1 % (w/v) NaCl and grew optimally in the absence of NaCl. The isoprenoid quinone of strain SYSUP0003^T was Q-10. The major fatty acids were C18 : 0, C16 : 0, C10 : 0 3-OH and summed feature 7. The polar lipids were diphosphatidylglycerol (DPG), aminophospholipids (AL), phosphatidylglycerol (PG), phosphatidylcholine (PC) and four unidentified polar lipids (L). The genome size was 3 204 685 bp, with a DNA G+C content of 69.7 mol%. The average nucleotide identity values between strain SYSUP0003^T and P. sediminis DSM 26170^T (ANIm 84.2 %, ANIb 75.6 %), Paracoccus solventivorans DSM 6637^T (ANIm 84.5 %, ANIb 76.9 %) and Paracoccus alkenifer DSM 11593^T (ANIm 84.3 %, ANIb 77.3 %) were below the cut-off level (95-96 %) for species delineation. Based on phenotypic, chemotaxonomic and molecular characterizations, strain SYSUP0003^T represents a novel species of the genus Paracoccus, for which the name Paracoccus endophyticus sp. nov. is proposed. The type strain is SYSUP0003^T (=KCTC 62180^T=CGMCC 1.16545^T).

Keywords: Gastrodia elata Blume; Paracoccus endophyticus; endophyte; genome analysis.