Antimicrobial Properties of the Endophytic Fungus Penicillium roqueforti 12Ph Isolated from the Plant Peganum harmala

Abstract

Peganum harmala L. is a medicinal herb native to Central Asia and Iran and has long been used in traditional medicine in many countries for the treatment of various diseases. Endophytic microorganisms inhabit plant tissues without causing apparent harm to their host and have attracted considerable scientific attention due to their ability to produce biologically active secondary metabolites, including antimicrobial compounds. In the present study, we investigated the antibacterial activity of secondary metabolites produced by the endophytic fungus Penicillium roqueforti 12Ph isolated from Peganum harmala. A total of fourteen fungal isolates were obtained from the plant tissues, among which isolate 12Ph demonstrated the strongest antimicrobial activity against pathogens, including Methicillin-resistant Staphylococcus aureus (MRSA) and Candida albicans. Molecular genetic identification based on sequence analysis confirmed that the isolate belongs to the species P. roqueforti. Preliminary phytochemical screening revealed the presence of several classes of bioactive compounds, including terpenoids, steroids, flavonoids, tannins, cardiac glycosides, and alkaloids. Further chemical characterization using gas chromatography–mass spectrometry (GC–MS) showed that the crude extract of P. roqueforti 12Ph and its chromatographic fractions contained compounds belonging to different chemical classes such as alkanes, fatty acids, and amino-containing compounds. The major detected constituents included methyl hexadecanoate, n-hexadecanoic acid, and 9,12-octadecadienoic acid (Z, Z). These findings suggest that the endophytic fungus P. roqueforti 12Ph associated with P. harmala may represent a promising source of antimicrobial secondary metabolites with potential pharmaceutical applications.