BAKTERI ENDOFIT YANG DIISOLASI DARI AKAR Eurycoma longifolia DAN POTENSINYA SEBAGAI PENGENDALI JAMUR PATOGEN TANAMAN - Sulistiyani, Tri Ratna; Meliah, Siti; Damayanti, . (Jurnal Bioteknologi & Biosains Indonesia (JBBI), 2020)
Eurycoma longifolia (pasak bumi) is known as a medicinal plant that contains biologically active compounds. Studies on endophytic bacteria associated with pasak bumi and their biocontrol activities have not been widely reported. The objective of this study is to isolate potential endophytic bacteria associated with E. longifolia possessing biocontrol activity against plant pathogenic fungi, Sclerotium rolfsii, Fusarium solani, F. oxysporum, and Colletotrichum gloeosporioides. Endophytic bacteria were isolated from the roots of E. longifolia using the plant piece method and identified based on 16S rRNA genes analysis. Antagonist test of bacterial isolates was conducted by dual confrontation method. The mechanisms of fungal growth inhibition were evaluated based on their ability to produce hydrolytic enzymes, antibiotic, and volatile organic compounds. Two isolates were obtained and identified as Stenotrophomonas maltophilia (Apb1) and Serratia marcescens (Apb2). Apb2 was able to inhibit the growth of four tested fungi and showed protease, chitinase as well as cellulase activities. The crude extract and volatile organic compound produced by Apb2 were active against F. solani growth.Keywords: biocontrol, endophytic, Eurycoma longifolia, fungi, inhibition mechanism ABSTRAKEurycoma longifolia (pasak bumi) dikenal sebagai tanaman obat yang mengandung beberapa senyawa aktif secara biologis. Penelitian mengenai bakteri endofit yang berasosiasi dengan tanaman pasak bumi berikut aktivitas biokontrolnya belum banyak dilaporkan. Penelitian ini bertujuan mengisolasi bakteri endofit potensial dari tanaman E. longifolia yang memiliki aktivitas biokontrol terhadap empat strain uji jamur patogen tanaman, yaitu Sclerotium rolfsii, Fusarium solani, F. oxysporum, dan Colletotrichum gloeosporioides. Bakteri endofit diisolasi dari akar E. longifola menggunakan metode plant piece dan diidentifikasi berdasarkan analisis gen 16S rRNA. Uji antagonis isolat bakteri dilakukan dengan metode konfrontasi ganda. Mekanisme penghambatan jamur patogen tanaman dievaluasi berdasarkan kemampuannya dalam memproduksi enzim hidrolisis, senyawa antibiotik, dan senyawa organik volatil. Dua isolat bakteri endofit berhasil diperoleh dan teridentifikasi sebagai Stenotrophomonas maltophilia (Apb1) dan Serratia marcescens (Apb2). Isolat Apb2 mampu menghambat pertumbuhan keempat jamur yang diuji dan menunjukkan aktivitas protease, kitinase dan selulase. Ekstrak kasar dan senyawa organik volatil yang dihasilkan oleh isolat Apb2 aktif menghambat pertumbuhan F. solani.