Paracoccus hibiscisoli sp. nov., isolated from the rhizosphere of Mugunghwa (Hibiscus syriacus)

A Gram-reaction-negative, aerobic, non-motile, short-rod-shaped bacterium (THG-T2.31T) was isolated from the rhizosphere of Mugunghwa (Hibiscus syriacus). Growth occurred at 10-35 °C (optimum 28 °C), at pH 5.0-8.0 (optimum pH 7.0) and with 0-4.0 % NaCl (optimum 1.0 %). Based on 16S rRNA gene sequence analysis, the nearest phylogenetic neighbours of strain THG-T2.31T were identified as Paracoccus marcusii DSM 11574T (98.4 %), Paracoccus haeundaensis BC74171T (98.3 %), Paracoccus carotinifaciens E-396T (98.3 %), Paracoccus aestuarii B7T (97.3 %) and Paracoccus seriniphilus MBT-A4T (97.0 %); levels of similarity with the type strains of other species of the genus Paracoccus were lower than 97.0 %. The polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one unidentified aminolipid and two unidentified phospholipids. The major fatty acids were C16 : 0, C18 : 0, C10 : 0 3-OH, and C18 : 1ω7c. The quinone was ubiquinone-10 (Q-10). The DNA G+C content of strain THG-T2.31T was 69.1 mol%. DNA-DNA hybridization values between strain THG-T2.31T and P. marcusii DSM 11574T, P. haeundaensis BC74171T, P. carotinifaciens E-396T, P. aestuarii B7T and P. seriniphilus MBT-A4T were 38.9 % (34.9 %, reciprocal analysis), 29.1 % (23.5 %), 28.0 % (19.7 %), 18.9 % (9.3) and 13.1 % (6.2 %). On the basis of the phylogenetic analysis, chemotaxonomic data, physiological characteristics and DNA-DNA hybridization data, strain THG-T2.31T represents a novel species of the genus Paracoccus, for which the name Paracoccus hibiscisoli sp. nov. is proposed. The type strain is THG-T2.31T (=KACC 18933T=CCTCC AB 2016182T).