Flavobacterium oryzae sp. nov., isolated from a flooded rice field, and emended descriptions of Flavobacterium flevense, Flavobacterium yonginense and Flavobacterium myungsuense

Abstract

A bacterial strain, designated Jyi-05T, was isolated from a flooded rice field and characterized using a polyphasic taxonomic approach. Cells of strain Jyi-05T were Gram-stain-negative, strictly aerobic, bright-yellow-pigmented rods that were motile by gliding. Growth occurred at 10–30 °C (optimum 30 °C), at pH 6.5–7.5 (optimum pH 7.0) and with 0–2 % (w/v) NaCl (optimum 1 %, w/v, NaCl). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain Jyi-05T belonged to the genus Flavobacterium and was most closely related to Flavobacterium flevense DSM 1076T with sequence similarity of 97.6 %. Strain Jyi-05T contained iso-C15 : 0 (16.6 %), anteiso-C15 : 0 (10.8 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 10.3 %), iso-C17 : 0 3-OH (9.2 %), C16 : 0 (7.3 %) and iso-C15 : 0 3-OH (7.2 %) as the predominant fatty acids. The major isoprenoid quinone was MK-6. The polar lipid profile consisted of phosphatidylethanolamine and several uncharacterized aminophospholipids and phospholipids. The major polyamine was homospermidine. The genomic DNA G+C content of strain Jyi-05T was 34.2 mol%. The DNA–DNA relatedness of strain Jyi-05T with respect to recognized species of the genus Flavobacterium was less than 70 %. On the basis of the phylogenetic inference and phenotypic data, strain Jyi-05T should be classified as a novel species, for which the name Flavobacterium oryzae sp. nov. is proposed. The type strain is Jyi-05T ( = BCRC 80522T = LMG 27292T = KCTC 32240T). Emended descriptions of Flavobacterium flevense , Flavobacterium yonginense and Flavobacterium myungsuense are also presented.