Microorganisms that grow in poorly studied environments are of special interest when new biotechnological applications are searched. The Melet river offshore sediments at the Black Sea have been described to contain an important number of contaminants from upstream industries which have been accumulating for years. Bacteria of such habitats must be adapted to the presence of those compounds and in some cases, are able to use them as carbon sources. In the analysis of some samples recovered from this environment, an actinobacterial strain was isolated, named as S1510(T), and its taxonomic position was determined using a combination of phenotypic and genotypic properties. Strain S1510(T) presented phenotypic properties typical of members of the family Micromonosporaceae and was assigned to the Plantactinospora genus, based on the phylogenetic analyses of the 16S rRNA gene and whole-genome sequences. Low dDDH (digital DNA-DNA hybridization) values with other members of the genus confirmed that Plantactinospora sp. S1510(T) represents a novel species, and is proposed with the new name Plantactinospora alkalitolerans. The strain presented characteristics not previously described for other species in the genus, such as its high tolerance to alkaline pHs, the presence of genes related to the production and degradation of alkanes (oleABCD, ssuAD, almA), the degradation of several aromatic compounds, and the tolerance to high heavy metal concentrations. In addition, Plantactinospora sp. S1510(T) presents several bioclusters to produce nonribosomal peptide-synthetases, terpenes, polyketide synthases, and bacteriocins, that possess low similarities with known compounds.