Genome-based classification of Micromonospora craterilacus sp. nov., a novel actinobacterium isolated from Nemrut Lake

A novel actinobacterial strain, designated NA12 T , was isolated from coastal sediment sample of Nemrut Lake, a crater lake in eastern Anatolia, Turkey. The taxonomic position of the strain was established using a polyphasic approach. Cultural and chemotaxonomic characteristics of the strain were consistent with its classification within the family Micromonosporaceae . The 16S rRNA gene sequence analysis of strain NA12 T showed that the strain closely related to M. radicis AZ1-13 T , M. zingiberis PLAI 1-1 T , M. craniella LHW63014 T and M. endophytica 202201 T with pairwise sequence identity values ranging from 99.4 to 99.3%. Digital DNA–DNA hybridization values between strain NA12 T and the closely related type strains were ranged from 41.0 to 18.3% while the average nucleotide identity values were between 87.3 and 86.5%, which are well below the designed cut-off points of 70 and 95%, respectively. The G + C content of genomic DNA was 71.5%. Whole-cell hydrolysates of strain NA12 T contained 3-hydroxydiaminopimelic acid and meso -diaminopimelic acid. Cell-wall sugars were composed of arabinose, fucose, glucose, mannose, rhamnose and xylose. The polar lipid profile contained phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol, phosphatidylglycerol, glycophospholipid, amino-phospholipid and two unidentified phospholipids. The predominant menaquinones were MK-9(H 6 ) and MK-9(H 4 ). Major fatty acids were iso -C 16:0 and C 17:1 ω8c. Based upon the consensus of phenotypic and phylogenetic analyses as well as whole genome comparisons, strain NA12 T (DSM 100982 T = KCTC 39647 T ) is proposed to represent the type strain of a novel species, Micromonospora craterilacus sp. nov.