Aeromicrobium changchenzhani sp. nov. and Streptomyces changchenzhani sp. nov., two novel actinomycetes isolated from soils of Ardley Island, Fildes Peninsula, Antarctica.
TL;DR
On the basis of polyphasic taxonomy analysis, strains Or2-10aT and 21So2-11T are concluded to represent two novel species of the genera Aeromicrobium and Streptomyces, respectively.
Abstract
Two Gram-stain-positive, non-motile actinomycetes, designated Or2-10aT and 21So2-11T, were isolated from ornithogenic and pristine soils collected on Ardley Island, Fildes Peninsula, King George Island, maritime Antarctica. 16S rRNA gene sequence analysis revealed that strains Or2-10aT and 21So2-11T showed the highest similarities to Aeromicrobium panaciterrae Gsoil 161T (98.02%) and Streptomyces drozdowiczii NRRL B-24297T (97.85%), respectively. Phylogenetic analyses based on 16S rRNA gene sequences confirmed the close relationships of these strains. Genomic analyses further supported the novel taxonomic status of these two species based on average nucleotide identity and digital DNA-DNA hybridization. Strains Or2-10aT and 21So2-11T contained MK-9 and MK-9 (H8) as the predominant menaquinone, respectively. High abundances of C18 : 1 ω9c and C16 : 0 were detected in Or2-10aT, whereas iso-C16 : 0, anteiso-C15 : 0 and iso-C16 : 1 h were dominant in 21So2-11T. The cell-wall peptidoglycan of both Or2-10aT and 21So2-11T contained ʟʟ-diaminopimelic acid. The whole-cell sugars of the two strains contained ribose and strain Or2-10aT contained additional glucose. Strain Or2-10aT contained diphosphatidylglycerol (DPG), phosphatidylglycerol, phosphatidylinositol (PI), an unidentified phospholipid and an unidentified phosphoglycolipid as major polar lipids, whereas strain 21So2-11T contained DPG, phosphatidylethanolamine, PI and phosphatidylinositol mannoside as major polar lipids. On the basis of polyphasic taxonomy analysis, strains Or2-10aT and 21So2-11T are concluded to represent two novel species of the genera Aeromicrobium and Streptomyces, respectively. The names Aeromicrobium changchenzhani sp. nov. (type strain Or2-10aT=CCTCC AA 2025019T = DSM 120837T=KCTC 59632T) and Streptomyces changchenzhani sp. nov. (type strain 21So2-11T = CCTCC AA 2024063T = DSM 121692T=JCM 38519T) are proposed.