<![CDATA[Infectious diseases suffered by many people are caused by several bacteria such as Escherichia coli, Staphylococcus aureus, Salmonella thyphi, Pseudomonas aeruginosa, Shigella dysenteriae, Vibrio cholera and Streptococcus mutans. Endophytic fungi can produce the same bioactive compounds as their host. The purpose of this study was to characterize macroscopically and microscopically endophytic fungi from the endemic plant of North Sulawesi leilem leaf (C. minahassae) and to examine the potential antibacterial activity of the endophytic fungus leilem leaf against pathogenic bacteria. The method used for the antibacterial test is the modified Kirby-bauer method. The results of this study, obtained 13 isolates of leilem leaf endophytic fungi that were isolated and characterized macroscopically and microscopically, namely JDL 7, JDL 10, JDL 12, JDL 16, JDL 17, JDL 18, JDL 20, JDL 21, JDL 22, JDL. 24, JDL 26, JDL 28. Four isolates of endophytic fungi that were effective as antibacterials were isolates JDL 8, JDL 26, JDL 28 against E. coli and JDL 18, JDL 26, JDL 28 against S. aureus. The endophytic fungal isolates which had the highest inhibition zone against E. coli were indicated by the isolate code JDL 26 with an average inhibition zone of 27 mm, while for S. aureus, the highest inhibition zone was indicated by the isolate code JDL 26 with an average inhibition zone of 29 mm.Keywords: Isolation, Leilem leaf, endophytic fungi, antibacterial Abstrak Penyakit infeksi yang banyak diderita masyarakat disebabkan oleh beberapa bakteri seperti Escherichia coli, Staphylococcus aureus, Salmonella thyphi, Pseudomonas aeruginosa, Shigella dysenteriae, Vibrio cholera dan Streptococcus mutans. Jamur endofit dapat menghasilkan senyawa-senyawa bioaktif yang sama dengan inangnya. Tujuan penelitian ini adalah untuk mengarakterisasi secara makroskopis dan mikroskopis jamur endofit dari tumbuhan endemik Sulawesi Utara daun leilem (C. minahassae) serta menguji potensi aktivitas antibakteri dari jamur endofit daun leilem terhadap bakteri patogen. Metode yang digunakan untuk uji antibakteri adalah metode Kirby-bauer. Hasil penelitian ini, diperoleh 13 isolat jamur endofit daun leilem yang berhasil diisolasi dan dikarakterisasi secara makroskopis dan mikroskopis, yaitu JDL 7, JDL 10, JDL 12, JDL 16, JDL 17, JDL 18, JDL 20, JDL 21, JDL 22, JDL 24, JDL 26, JDL 28. Empat isolat jamur endofit yang efektif sebagai antibakteri yaitu isolat JDL 8, JDL 26, JDL 28 terhadap E. coli dan JDL 18, JDL 26, JDL 28 terhadap bakteri S. aureus. Isolat jamur endofit yang memiliki zona hambat tertinggi terhadap bakteri E. coli ditunjukkan pada kode isolat JDL 26 dengan rerata zona hambat 27 mm sedangkan untuk bakteri S. aureus, zona hambat tertinggi ditunjukkan pada kode isolat JDL 26 dengan rerata zona hambat 29 mm.Kata kunci: Isolasi, daun Leilem, jamur endofit, antibakteri ]]>
