sp. nov., and sp. nov., two novel actinomycetal species isolated from macroalgae collected in the northern Portuguese coast.

Two novel actinomycetal strains, designated CC-R113 and CC-R104, were isolated from the tissues of two macroalgae collected on the northern Portuguese coast. Phylogenetic analyses based on the 16S rRNA gene showed that strain CT-R113 belongs to the genus , being closely related to 66/93 and VKM Ac-1457, with 98.65 and 98.39 % sequence similarity, respectively. The clade formed between the three type strains was confirmed by phylogenomic analysis. The genome of strain CT-R113 was 7.27 Mb in size with a G+C content of 71.3 mol %, with average nucleotide identity (ANI) values of 89.59 and 90.14 % with strains 66/93 and VKM Ac-1457, respectively. The major cellular fatty acids were identified as C 9, iso-C and anteiso-C. Menaquinone 10 (MK-10) was the major respiratory quinone. Comparative analysis of 16S rRNA gene sequences showed that strain CC-R104 belongs to the genus and is most closely related to DSM 44555, with 98.24 % sequence similarity. However, phylogenomic analysis revealed that strain CC-R104 establishes a clade with DSM 45380, being more distant from DSM 44555. The genome of strain CC-R104 was 5.34 Mb in size with a G+C content of 67.01 mol%. The ANI value between strains CC-R104 and DSM 45380 was 81.2 % and between strains CC-R104 and DSM 44555 was 81.5 %. The major cellular fatty acids were identified as C 9, C and summed feature 3. Menaquinone 8 (MK-8) was the only respiratory quinone. For both CC-R113 and CC-R104, optimum growth was observed at pH 7.0, 28 °C and 0-5 % NaCl and whole-cell hydrolysates contained -diaminopimelic acid as the cell-wall diamino acid. On the basis of phenotypic, molecular and chemotaxonomic characteristics, strains CT-R113 and CC-R104 are considered to represent novel species, for which the names sp. nov. (type strain CT-R113=LMG33234=UCCCB172) and sp. nov. (type strain CC-R104=LMG33233=UCCCB171) are proposed.