RESUMO
During a bioprospection of bacteria with antimicrobial activity, the actinomycete strain A38T was isolated from a sediment sample of the Carpintero river located in the Gran Piedra Mountains, Santiago de Cuba province (Cuba). This strain was identified as a member of the genus Micromonospora by means of a polyphasic taxonomy study. Strain A38T was an aerobic Gram-positive filamentous bacterium that produced single spores in a well-developed vegetative mycelium. An aerial mycelium was absent. The cell wall contained meso-diaminopimelic acid and the whole-cell sugars were glucose, mannose, ribose and xylose. The major cellular fatty acids were isoC15:0, 10 methyl C17:0, anteiso-C17:0 and iso-C17:0. The predominant menaquinones were MK-10(H4) and MK-10(H6). Phylogenetic analysis of 16S rRNA gene sequences revealed that this strain was closely related to Micromonospora tulbaghiae DSM 45142T (99.5â%), Micromonospora citrea DSM 43903T (99.4â%), Micromonospora marina DSM 45555T (99.4â%), Micromonospora maritima DSM 45782T (99.3â%), Micromonospora sediminicola DSM 45794T (99.3â%), Micromonospora aurantiaca DSM 43813T (99.2â%) and Micromonospora chaiyaphumensis DSM 45246T (99.2â%). The results of OrthoANIu analysis showed the highest similarity to Micromonospora chalcea DSM 43026T (96.4â%). However, the 16S rRNA and gyrB gene sequence-based phylogeny and phenotypic characteristics provided support to distinguish strain A38T as a novel species. On the basis of the results presented here, we propose to classify strain A38T (=LMG 30467T=CECT 30034T) as the type strain of the novel species Micromonospora fluminis sp. nov.