Idramsa Idramsa, Angela Glorya Marito Samosir, Nur Riski Ababil
The emergence of antibiotic-resistant pathogenic bacteria poses a major threat to public health, emphasizing the importance of discovering new antibiotic compounds. Endophytic microorganisms are known for producing a variety of antibiotics and other bioactive substances. They can generate a broad spectrum of secondary metabolites with potent antibacterial activity. Endophytes are microorganisms that form symbiotic relationships within plant tissues without causing obvious disease to the host plant. Microbes that live in extreme environments develop unique adaptive mechanisms and can produce novel bioactive compounds. Bacteria in such harsh conditions often develop specialized metabolic pathways, resulting in the production of distinctive secondary metabolites. This study aimed to isolate endophytic actinomycetes from the roots of the silver fern (Pityrogramma calomelanos (L.) Link), which grows in soil exposed to the eruption of Mount Sinabung in Karo Regency, North Sumatra Province, Indonesia. Antimicrobial screening of these isolates was performed using a dual culture assay to assess their ability to inhibit pathogenic bacteria. The endophytic actinomycete isolate AE9 showed activity against Staphylococcus aureus, Bacillus cereus, and Citrobacter freundii. Morphological, physiological, biochemical, and 16S rRNA gene sequence analyses confirmed that isolate AE9 is related to Streptomyces sp. VEL 17. These results suggest that endophytic actinomycetes from silver ferns growing in volcanically affected environments contain antibacterial bioactive compounds. © 2026, Bulgarian Society for Microbiology (Union of Scientists in Bulgaria). All rights reserved.
Biology, Mathematics, and Natural Science, Universitas Negeri Medan, Indonesia
