Pseudoflavitalea rhizosphaerae gen. nov., sp. nov., isolated from rhizosphere of tomato, and proposal to reclassify Flavitalea soli as Pseudoflavitalea soli comb. nov.

Abstract

A bacterial strain, designated T16R-265T, was isolated from rhizosphere of tomato in Buyeo-gun, Chungcheongnam-do, South Korea. The strain was Gram-stain-negative, aerobic, non-flagellated and rod- or long-rod-shaped. It grew at the range of 10-40 °C (optimum 28-30 °C), pH 6.0-9.0 (optimum pH 7.0) and with 0-3 % (w/v) NaCl (optimum 0 %). 16S rRNA gene sequence analysis showed that strain T16R-265T had the highest sequence similarity (98.0 %) with Flavitalea soli KIS20-3T and low sequence similarities of below 95 % with all other taxa. The phylogenetic tree revealed that the strain formed a robust monophyletic line with Flavitalea soli KIS20-3T separable from other clades. The predominant quinone of strain T16R-265T was MK-7, the polar lipids consisted of large amounts of phosphatidylethanolamine and an unknown lipid, and the major fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G. DNA-DNA hybridization values with Flavitalea soli KACC 17319T were below 70 %. The DNA G+C content of strain T16R-265T is 46.2 mol%. Based on phylogenetic evidence and the results of phenotypic, genotypic and chemotaxonomic analyses, strain T16R-265T represents a novel species of a new genus, for which the name Pseudoflavitalea rhizosphaerae gen. nov., sp. nov. is proposed. The type strain of the type species is T16R-265T (=KACC 18655T=NBRC 111880T). We also propose the reclassification of Flavitalea soli as Pseudoflavitalea soli comb. nov. (type strain KIS20-3T=KACC 17319T=JCM 19937T).