Taxonomic descriptions of Nocardia anocheti sp. nov. and Streptomyces odontomachicola sp. nov. isolated from ants

Two novel actinomycete strains, AG03ᵀ and ODS28ᵀ, were isolated from worker ants Anochetus graeffei and Odontomachus simillimus, respectively, collected in Thailand. Strain AG03ᵀ exhibited the highest 16S rRNA gene sequence similarity (98.28%) to Nocardia grenadensis NBRC 108939ᵀ, whereas strain ODS28ᵀ showed the highest similarity (97.73%) to Actinacidiphila bryophytorum NEAU-HZ10ᵀ. Chemotaxonomic analysis of AG03ᵀ revealed the presence of meso-diaminopimelic acid in the cell wall, glucose and mannose as whole-cell sugars, and MK-8(H₄ω-cycl) as the predominant menaquinone. In contrast, ODS28ᵀ contained LL-diaminopimelic acid, glucose, ribose, and xylose as whole-cell sugars, with MK-9(H₈) and MK-9(H₆) as the predominant menaquinones. Whole genome sequence-based relatedness values, including average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH), supported the classification of both strains as representing novel species. Based on polyphasic taxonomic evidence, strains AG03ᵀ and ODS28ᵀ are proposed as the type strains of Nocardia anocheti sp. nov. (AG03ᵀ = TBRC 16206ᵀ = NBRC 115864ᵀ) and Streptomyces odontomachicola sp. nov. (ODS28ᵀ = TBRC 18345ᵀ = NBRC 116641ᵀ), respectively. The genomes of both strains contained biosynthetic gene clusters (BGCs) potentially responsible for the production of bioactive secondary metabolites. These findings suggest that social insects, such as ants, represent a promising source of novel actinomycetes.