Actinomycetospora termitidis sp. nov., an insect-derived actinomycete isolated from termite (Odontotermes formosanus)

Abstract

Strain Odt1-22^T, an insect-derived actinomycete was isolated from a termite (Odontotermes formosanus) that was collected from Chanthaburi province, Thailand. Strain Odt1-22^T was aerobic, Gram-stain-positive, and produced bud-like spore chain on the substrate hypha. According to chemotaxonomic analysis, strain Odt1-22^T contained meso-diaminopimelic acid in peptidoglycan and the whole-cell hydrolysates contained arabinose, galactose, glucose, and ribose. The major menaquinone was MK-8(H₄). The diagnostic phospholipids were diphosphatidylglycerol, hydroxyphosphatidylethanolamine, phosphatidylethanolamine and phosphatidylglycerol. Phylogenetic analysis based on 16 S rRNA gene sequence revealed that strain Odt1-22^T was identified to the genus Actinomycetospora and showed high similarity values with A. chiangmaiensis DSM 45062 ^T (99.24%), A. soli SF1^T (99.24%) and A. corticicola 014-5 ^T (98.17%). The genomic size of strain Odt1-22^T was 6.6 Mbp with 73.8% G + C content and 6355 coding sequences (CDSs). The genomic analysis, strain Odt1-22^T and closely related species A. chiangmaiensis DSM 45062 ^T, A. soli SF1^T and A. corticicola DSM 45772 ^T displayed the values of average nucleotide identity-blast (ANIb) at 83.7-84.1% and MUMmer (ANIm) at 86.6-87.0%. Moreover, the results of digital DNA-DNA hybridization values between strain Odt1-22^T and related Actinomycetospora species were 45.8-50.5% that lower than the threshold value of commonly used to delineate separated species level. On the basis of phenotypic, chemotaxonomic, and genotypic data, strain Odt1-22^T represented a novel species within the genus Actinomycetospora, for which the name Actinomycetospora termitidis sp. nov. is proposed. The type strain of the species is Odt1-22^T (= TBRC 16192 ^T = NBRC 115965 ^T).