Flectobacillus rhizosphaerae sp. nov., isolated from the rhizosphere soil of Oryza sativa (L.), and emended description of the genus Flectobacillus

Abstract

A Gram-stain-negative, aerobic, pale orange, rod-shaped, non-motile bacterial strain, designated JC289T was isolated from a rhizosphere soil sample of the plant Oryza sativa (L.). 16S rRNA gene sequence analysis clearly allocated strain JC289T to the Flectobacillus cluster, showing highest sequence similarities to Flectobacillus roseus GFA-11T (99.5 %), Flectobacillus major ATCC 29496T (96.7 %) and Flectobacillus lacus CL-GP79T (94.6 %). Major (>5 %) fatty acids of strain JC289T were C16 : 1ω5c, iso-C15 : 0, C15 : 0 2-OH, iso-C15 : 0 3-OH and C16 : 1ω7c/C16 : 1ω6c, with minor amounts (>1– < 5 %) of C14 : 0, C16 : 0, anteiso-C15 : 0, C16 : 0 3-OH, iso-C17 : 0 3-OH, anteiso-C17 : 1B and/or iso-C17 : 1I. Menaquinone-7 was the major quinone of strain JC289T, and the polar lipid profile contained phosphatidylethanolamine, five unidentified aminophospholipids, two unidentified phospholipids, two unidentified aminolipids, two unidentified glycolipids and five unidentified lipids. DNA–DNA relatedness values of strain JC289T with Flectobacillus roseus LMG 24501T and Flectobacillus major LMG 13163T were 24.6 % (31.4 %, reciprocal analysis) and 16.2 % (22.4 %), respectively. On the basis of 16S rRNA gene sequence analysis, physiological and biochemical test results, and chemotaxonomic analysis, strain JC289T can be differentiated from its closest relatives in the genus Flectobacillus. Based on the data presented, it is concluded that strain JC289T represents a novel species of the genus Flectobacillus, for which the name Flectobacillus rhizosphaerae sp. nov. is proposed. The type strain is JC289T ( = KCTC 42575T = LMG 28712T).