Potensi antagonisme senyawa metabolit sekunder asal bakteri endofit dengan pelarut metanol terhadap jamur G. boninense Pat.

Sari

ABSTRACT
Antagonism potency of secondary metabolites produced by endophytic bacteria in methanol against pathogenic fungi Ganoderma boninense Pat.
The research aimed to determine the antifungal effect of secondary metabolites produced by endophytic bacteria of healthy root oil palm tree against the growth of Ganoderma boninense, the causal agent of basal stem rot disease on oil palm tree. Endophytic bacteria isolates (BEK5, BEK6, BEK7, BEK8, BEK9, BEK10 dan BEK11) were grown on ISP2 agar media for 14 days and extracted using methanol. Following extraction, the methanol was evaporated using rotary evaporator and the filtrat was sterilized using membrane filter 0.2 μm. The effect of the secondary metabolites against G. boninense was tested using agar well diffusion method. The observation on the colony growth and morphologicy of G. boninense mycelia were done at 7 days after treatment. The result demonstrated that all of the endophytic bacteria were able to produce seconday metablites that has antifungal effect on the growth of G. boninense. The highest growth inhibition was shown by secondary metabolites produced by BEK6 with inhibition of 22.89%. Furthermore, the secondary metabolites produced by all of the endophytic bacteria were caused morphological changes on the mycelia of G. boninense.
Keywords; Antifungal, Inhibition, Malformation
ABSTRAK
Penelitian ini bertujuan untuk mengetahui kemampuan antijamur metabolit sekunder yang dihasilkan oleh bakteri endofit asal akar tanaman kelapa sawit untuk menghambat pertumbuhan jamur patogen Ganoderma boninense, penyebab penyakit busuk pangkal batang pada tanaman kelapa sawit. Isolat-isolat bakteri endofit (BEK5, BEK6, BEK7, BEK8, BEK9, BEK10 dan BEK11) ditumbuhkan pada media ISP2 agar selama 14 hari dan kemudain diekstraksi dengan pelarut metanol. Metanol diuapkan menggunakan rotary evaporator dan filtrat yang dihasilkan disterilkan menggunakan membran filter berukuran 0,2 μm. Pengujian pengaruh senyawa metabolit sekunder terhadap pertumbuhan jamur G. boninense dilakukan dengan metode agar well diffusion. Pengamatan terhadap pertumbuhan koloni jamur G. boninense dan morfologi miselia G. boninense dilakukan pada 7 hari setelah perlakuan. Hasil penelitian menunjukkan semua isolat bakteri endofit mengeluarkan senyawa metabolit sekunder yang dapat menghambat pertumbuhan jamur G. boninense. Penghambatan pertumbuhan koloni jamur G. boninense tertinggi sebesar 22,89% ditemukan pada perlakuan metabolit sekunder asal bakteri BEK6. Pengamatan terhadap morfologi jamur G. boninense menunjukkan bahwa senyawa metabolit sekunder yang dihasilkan oleh isolat-isolat bakteri endofit tersebut dapat menyebabkan perubahan morfologi miselia G. boninense.
Kata kunci: Antifungal, Penghambatan, Malformasi