RESUMEN

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 (99.5 %), Micromonospora citrea DSM 43903T (99.4 %), Micromonospora marina DSM 45555T (99.4 %), Micromonospora maritima DSM 45782T (99.3 %), Micromonospora sediminicola DSM 45794T (99.3 %), Micromonospora aurantiaca DSM 43813T (99.2 %) and Micromonospora chaiyaphumensis DSM 45246T (99.2 %). The results of OrthoANIu analysis showed the highest similarity to Micromonospora chalcea DSM 43026T (96.4 %). 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.

Asunto(s)

Sedimentos Geológicos/microbiología , Micromonospora/clasificación , Filogenia , Ríos/microbiología , Técnicas de Tipificación Bacteriana , Composición de Base , Cuba , ADN Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Grasos/química , Micromonospora/aislamiento & purificación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/química

RESUMEN

An actinomycete, strain D1T, was isolated from a freshwater sediment sample collected from the San Pablo river in the La Risueña community, Santiago de Cuba province, Cuba. The strain was identified as a member of the genus Nocardiopsis by means of a polyphasic taxonomic study. It produced a light yellow non-fragmented substrate mycelium, a white well-developed aerial mycelium and straight to flexuous hyphae. No specific spore chains were observed. Strain D1T contained meso-diaminopimelic acid, no diagnostic sugars, and MK-10(H2), MK-10(H4), MK-10 and MK-10(H6) as predominant menaquinones, but not phosphatidylcholine as diagnostic polar lipid of the genus Nocardiopsis. The predominant fatty acids were iso-C16 : 0, 10-methyl-C18 : 0 and anteiso-C17 : 0. Strain D1T showed the highest degree of 16S rRNA gene sequence similarity to Nocardiopsis synnematoformans DSM 44143T (99.8 %), Nocardiopsis dassonvillei subsp. albirubida NBRC 13392T (99.8 %) and Nocardiopsis dassonvillei subsp. dassonvillei DSM 43111T (99.6 %). A genomic OrthoANIu value between D1T and N. dassonvillei subsp. dassonvillei DSM 43111T of 97.63 % and a dDDH value of 78.9 % indicated that strain D1T should be classified in N. dassonvillei. However, phenotypic characteristics distinguished strain D1T from its nearest neighbour taxon. On basis of these results we propose to classify strain D1T (=LMG 30468T=CECT 30033T) as a representative of a novel subspecies of the genus Nocardiopsis, for which the name Nocardiopsis dassonvillei subsp. crassaminis subsp. nov. is proposed. In addition, the genomic distance between N. dassonvillei subsp. albirubida NBRC 13392T and N. dassonvillei subsp. dassonvillei DSM 43111T as determined through OrthoANIu (93.64 %) and dDDH (53.40 %), along with considerable phenotypic and chemotaxonomic differences reported in earlier studies, indicated that the classification of this taxon as Nocardiopsis alborubida Grund and Kroppenstedt 1990 is to be preferred over its classification as N. dassonvillei subsp. albirubida Evtushenko et al. 2000.

Asunto(s)

Agua Dulce/microbiología , Sedimentos Geológicos/microbiología , Nocardiopsis/clasificación , Filogenia , Técnicas de Tipificación Bacteriana , Composición de Base , Cuba , ADN Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Grasos/química , Nocardiopsis/aislamiento & purificación , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/química