Genome Sequencing and Comparative Analysis of Nocardiopsis moroccensis nov., a Halotolerant Actinomycetota from Moroccan Hypersaline Ecosystem

Saline and arid ecosystems are recognized as promising reservoirs of novel actinomycetes with unique adaptations and secondary metabolism potential. In this study, a halotolerant actinomycetota strain, designated ZS3416R2A, was isolated from saline soil in the hypersaline wetland of Lake Zima, Morocco. Phylogenetic analysis using the 16S rRNA gene sequence showed 99.03% similarity to Nocardiopsis terrae DSM 45157, indicating a close affiliation with the genus Nocardiopsis . Whole-genome sequencing revealed a 6.1 Mb circular chromosome with a G + C content of 70.48 mol% and 5,855 coding sequences. Genome-based metrics (ANI 95.07%, dDDH 66.4%) supported its classification as a novel species distinct from N. terrae , while AAI (95.87%) and POCP (82.4%) confirmed its placement within the genus. Comparative analyses revealed unique gene families, biosynthetic gene clusters, and regions of genomic plasticity in ZS3416R2A. Phenotypically, ZS3416R2A grew over a broad range of salinity (0–15%), temperature (16–37°C), and pH (7.0–8.0), with denser aerial mycelium formation than DSM 45157, reflecting adaptation to the arid saline environment of Lake Zima. Chemotaxonomic characterization identified MK-10(H ₆ ), MK-10(H ₄ ) and MK-9(H ₄ ) as predominant menaquinones, iso-C16:0 and 10-methyl-C18:0 as major fatty acids, and diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, and phosphatidylinositol as major polar lipids. Based on these polyphasic evidences, strain ZS3416R2A represents a novel species within the genus Nocardiopsis , for which the name Nocardiopsis moroccensis sp. nov. is proposed. The type strain is ZS3416R2A ^T (= CCMM B1332 ^T  = DSM 120542 ^T ).