Whole Genome Sequence-Based Classification of Nonomuraea marmarensis sp. nov., Isolated from Island Soil

Abstract

Actinomycetes are known to produce a vast array of bioactive secondary metabolites with potential therapeutic applications, including antimicrobials, anticancer agents, and enzyme inhibitors. Among these, members of the genus Nonomuraea have received much attention due to their broad ecological importance in nutrient cycling in soil and their ability to produce new bioactive compounds. A novel actinomycetes, designated strain M3C6T, was isolated from soil samples collected on Marmara Island, located in the Istanbul province, aiming to explore the microbial diversity of unexplored habitats, and characterized using a polyphasic approach. The isolate showed chemotaxonomic and morphological features consistent with members of the genus Nonomuraea. The 16S rRNA gene sequence analysis revealed that strain M3C6T shared the highest similarity, at 98.7% sequence identity, to Nonomuraea basaltis 160415T and Nonomuraea turkmeniaca DSM 43926T. However, the ANI and dDDH values between strain M3C6T and these reference strains were fairly low, ranging from 84.0 to 84.6% and 31.8 to 33.7%, respectively, below the generally accepted cutoffs for ANI and DDH that delineate different prokaryotic species. Genomic analysis of strain M3C6T showed that it had a genome size of 10.38 Mbp and a DNA G+C content of 69.5 mol%. Based on these chemotaxonomic, phenotypic, and genomic data, strain M3C6T is classified as a novel species within the genus Nonomuraea, for which the name Nonomuraea marmarensis sp. nov. is proposed. The type strain is M3C6T (= KCTC 49983T = CGMCC 4.8035T). Genomic analyses confirmed the high potential of M3C6T to produce specialized secondary metabolites.