Gottfriedia endophyticus sp. nov., a novel indole-acetic acid producing bacterium isolated from the roots of rice plant

A Gram-stain-positive, aerobic, motile and rod-shaped bacterium, designated RG28(T), was isolated from the roots of rice plant collected from paddy fields in Ilsan, South Korea. Cells of the strain were oxidase-negative but catalase-positive. Strain RG28(T) was found to grow at 10-50 degrees C (optimum, 25-30 degrees C), pH 5.0-10.0 (optimum, pH 7.0) and in 1.0-5.0% (w/v) NaCl (optimum, 0%). The cell-wall peptidoglycan contained meso-diaminopimelic acid and the predominant menaquinones were MK-7 and MK-6. The predominant cellular fatty acids were C-16:0, iso-C-15:0 and anteiso-C-15:0. The major polar lipids included phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, four unidentified aminophosphoglycolipids, four unidentified aminophospholipids, two unidentified glycolipids, one unidentified aminoglycolipid and four unidentified lipids. The genomic DNA G + C content was 33.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain was closely related to Gottfriedia acidiceleris CBD 119(T) (98.6%), Gottfriedia solisilvae LMG 18422(T) (98.5%) and Gottfriedia luciferensis LMG 18422(T) (98.4%). The average nucleotide identity (ANI) and in silico DNA-DNA hybridization (isDDH) values between strain RG28(T) and type strains of Gottfriedia species were lower than the cut-offs (>= 95-96% for ANI and >= 70% for is DDH) required to define a bacterial species. Meanwhile, the strain has the ability to produce indole-acetic acid (40.5 mu g/mL). Phylogenetic, physiological and chemotaxonomic data suggested that strain RG28(T) represented a novel species of the genus Gottfriedia, for which the name Gottfriedia endophyticus sp. nov. is proposed, with the type strain RG28(T) (= KCTC 43327(T) = TBRC 15151(T)).

Automated summary

A new bacterium strain RG28(T) was isolated from the roots of rice plant collected from paddy fields in South Korea. It belongs to the genus Gottfriedia and has some unique physiological and chemical characteristics, as well as the ability to produce indole-acetic acid.