Atacama desert is a source of new Micromonospora strains: description of Micromonospora sicca sp. nov

Several strains were isolated from subsurface soil of the Atacama Desert and were previously assigned to the Micromonospora genus. A polyphasic study was designed to determine the taxonomic affiliation of isolates 4G51^T, 4G53, and 4G57. All the strains showed chemotaxonomic properties in line with their classification in the genus Micromonospora, including meso-diaminopimelic acid in the cell wall peptidoglycan, MK-9(H₄) as major respiratory quinone, iso-C_15:0 and iso-C_16:0 as major fatty acids and diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol as major polar lipids. The 16S rRNA gene sequences of strains 4G51^T, 4G53, and 4G57 showed the highest similarity (97.9 %) with the type strain of Micromonospora costi CS1-12^T, forming an independent branch in the phylogenetic gene tree. Their independent position was confirmed with genome phylogenies, being most closely related to the type strain of Micromonospora kangleipakensis. Digital DNA-DNA hybridization and average nucleotide identity analyses between the isolates and their closest phylogenomic neighbours confirmed that they should be assigned to a new species within the genus Micromonospora for which the name Micromonospora sicca sp. nov. (4G51^T=PCM 3031^T=LMG 30756^T) is proposed.