Pseudonocardia terrae sp. nov., an actinobacterium isolated from rice rhizosphere soil in Thailand

A novel actinomycete, designated strain RS11V-5(T), was isolated from rhizosphere soil of Oryza sativa L. collected from Roi Et Province, Thailand, and its taxonomic position was evaluated. Cells of strain RS11V-5T were Gram-stain-positive, aerobic, and non-motile. Whole-cell hydrolysates contained meso-diaminopimelic acid, arabinose, galactose, glucose and ribose. MK-8(H-4) was detected as the predominant menaquinone of this strain. The polar lipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, hydroxy-phosphatidylmethylethanolamine, hydroxy-phosphatidylethanolamine, an unidentified phospholipid, an unidentified aminolipid and an unidentified glycolipid. The major fatty acids were iso-C-16:0, C-16:0 and C-16:1 omega 7c/C-16:1 omega 6c. Phylogenetic analyses based on the 16S rRNA gene sequences showed that strain RS11V-5(T) belonged to the genus Pseudonocardia and had high 16S rRNA sequence similarity of 99.3% to Pseudonocardia kujensis KCTC 29062(T) and less than 98.4 % to other members of the genus Pseudonocardia. The DNA G+C content of the strain RS11V-5(T) was 73.3mol%. Strain RS11V-5(T) showed 46.5 % digital DNA-DNA hybridization, 92.2% orthologous average nucleotide identity (OrthoANI), 90.2 % ANI based on blast and 92.7% ANI based on MUMmer to P. kujensis KCTC 29062(T). Based its phenotypic, genotypic, phylogenetic and chemotaxonomic characteristics, strain RS11V-5(T) represents a novel species of the genus Pseudonocardia, for which the name Pseudonocardia terrae sp. nov. is proposed. The type strain is RS11V-5(T) (=TBRC 15286(T)=NBRC 115296(T)).

Automated summary

A novel actinomycete, designated as Pseudonocardia terrae sp. nov., was isolated from rhizosphere soil of Oryza sativa L. collected from Thailand. The strain showed distinct phenotypic, genotypic, phylogenetic, and chemotaxonomic characteristics compared to other members of the genus Pseudonocardia.