STREPTOMYCES SPP. FROM WAR-IMPACTED SOILS: WHOLE-GENOME ANALYSIS, METABOLITE PROFILING, AND ANTAGONISTIC ACTIVITY AGAINST PHYTOPATHOGENS

Abstract

Fifty streptomycete isolates were recovered from war-impacted soils, of which nine of the most antagonistically active strains were selected for further study based on dual-culture screening against fungi and bacteria. Strains Y15, SK4, SK14 and SK16 displayed the strongest and broadest inhibitory activity, with Y15 producing the largest inhibition zones overall, notably against Bipolaris sorokiniana (27.9 ± 0.2 mm) and Xanthomonas campestris (15.8 ± 0.5 mm). Whole-genome sequencing and orthoANI analysis identified Streptomyces sp. SK4 as S. lidicus (100% identity), while Y15, SK16 and SK14 showed at most 88–92 % identity to their closest relatives. Genome mining with antiSMASH revealed a conserved biosynthetic core shared by Y15 and SK4 alongside seven strain-specific biosynthetic gene clusters in each, and LC-HRMS profiling confirmed production of reedsmycin F and youssoufene A1 by Y15 and streptolydigin by SK4. These findings highlight war-impacted soils as a valuable, underexplored source of biotechnologically promising streptomycetes.