Amnibacterium setariae sp. nov., an endophytic actinobacterium isolated from dried foxtail.

Abstract

A Gram-stain positive, short rod-shaped, aerobic, motile by means of gliding, yellow-pigmented actinobacterium, designated strain DD4aT, was isolated from dry yellow foxtail. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain DD4aT is closely related to Amnibacterium soli MB78T (98.4% similarity), Amnibacterium kyonggiense KSL51201-037T (98.2%) and Amnibacterium endophyticum 1T4Z-3T (97.43%). Strain DD4aT forms yellow colonies on R2A agar medium. The peptidoglycan was found to contains diaminopimelic acid (which is a diagnostic cell wall diamino acid), alanine, glutamic acid and lysine. The polar lipids diphosphatidylglycerol, phosphatidylglycerol, six unidentified glycolipids and an unidentified polar lipid were found to be present in strain DD4aT. The major cellular fatty acids anteiso-C15:0 (42.9%) and iso-C16:0 (34.6%) were found in strain DD4aT. The predominant respiratory quinones were found to be MK-11 and MK-12. The DNA G+C content of strain DD4aT is 73.9mol%. DNA-DNA relatedness of strain DD4aT with A. soli MB78T, A. kyonggiense KSL51201-037T, and A. endophyticum 1T4Z-3T were 53.3% (± 1.1%), 47.0% (± 0.5%), and 47.9% (± 0.9%), respectively. The digital DNA-DNA hybridisation and average nucleotide identity values between strain DD4aT and A. kyonggiense KSL51201-037T were determined to be 26.1% and 82.7%. On the basis of phenotypic, genotypic, chemotaxonomic and phylogenetic analysis, DD4aT represents a novel member of the genus Amnibacterium, for which the name Amnibacterium setariae sp. nov., is proposed. The type strain of Amnibacterium setariae is DD4aT (= KACC 19817T = JCM 32878T).