Planobacterium oryzisoli sp. nov., a novel bacterium isolated from roots of rice plant

Abstract

A Gram-negative, aerobic, short rod-shaped, non-motile, non-spore forming bacterium, designated strain GCR5(T), was isolated from soil of paddy field. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain GCR5(T) belongs to the genus Planobacterium and is related to Planobacterium taklimakanense NCTC 13490( T) (96.1%, 16S rRNA gene sequence similarity). Colonies on R2A were white but they turn into bright yellow after exponential growth. They produce carotenoid pigment after 5-6 days of incubation, before that carotenoid pigment was not found. The major isoprenoid quinone was MK-6, and major cellular fatty acids were iso-C-15:0, anteiso-C-15:0 and iso-C-17:0 3OH. Polar lipids include phosphatidylethanolamine, three unidentified phosphoglycolipids, three unidentified glycolipids, one unidentified aminophosphoglycolipid and five unidentified polar lipids. The strain GCR5(T) was found to have a 2,106,200 bp linear genome with G + C content of 43.7%. The ANI, dDDH and AAI values between the strain GCR5T and the type strains of phylogenetically related species were 60.2-71.1%, 19-24.3%, and 60.2-69.6%, respectively. The strain designated GCR5(T) produced indole acetic acid (IAA) in the presence of tryptophan only, and auxin responsive genes and tryptophan biosynthesis genes were found in its genome. Based on its polyphasic characteristics, strain GCR5(T) represents a novel species within the genus Planobacterium, for which the name Planobacterium oryzisoli sp. nov. was proposed. The type strain is GCR5(T) (= KCTC 82713 (T) = TISTR 2996( T) = TBRC 15746 (T)).