Abstract: The genus Micromonospora, a globally distributed actinomycete inhabiting diverse ecosystems, is widely recognized for its remarkable biosynthetic capacity and role as a prolific source of bioactive natural products. However, the members of the genus Micromonospora from extreme environment remain largely unstudied. In this study, we isolated 15 Micromonospora spp. strains from samples collected in desert and marine habitats. Based on polyphasic taxonomy approaches eight strains were identified and represent four novel species. Genome mining of the newly isolated strains revealed substantial biosynthetic potential for terpenes (n=70, 22.9% of total biosynthetic gene clusters, BGCs) and polyketides (n=60, 19.6% of total BGCs). Subsequent pan-genomic analysis identified substantial numbers of terpene-related (n=745, 33.8% of total biosynthetic genes, BGs) and polyketide-related (n=728, 33.0%) BGs in the core genome, highlighting their core biosynthetic potential. To further investigate their metabolic capacity, fermentation and metabolomic profiling were conducted to assess the secondary metabolite production capacity of all 15 strains. The results revealed a diverse array of alkaloids (averaging 75.3, 33.4% of total annotated secondary metabolites) and amino acid-derived peptides (averaging 56.3, 25.0% of total). These findings also highlight significant metabolic variations among strains and underscore the pivotal role of fermentation conditions in shaping their metabolic profiles. This study advances the taxonomic and functional understanding of Micromonospora spp. and presents a multi-omics framework combining genome mining and metabolomics to explore the biosynthetic potential of wild-type strains from extreme habitats.

Key words: desert and marine habitats, genome mining, metabolomics, Micromonospora, multi-omics analysis, polyphasic taxonomy.