ABSTRAK Aktinomisetes merupakan salah satu kelompok bakteri Gram-positif dengan kemampuan menghasilkan antibiotik bermanfaat bagi manusia. Aktinomisetes juga dapat diisolasi dari berbagai jenis lingkungan, salah satunya liken pohon. Penelitian bertujuan untuk meneliti diversitas aktinomisetes diisolasi dari liken di kawasan Cibinong Science Center (CSC) dan Kebun Raya Cibodas (KRC) serta menganalisis profil metabolit sekunder antimikroba isolat terhadap mikroorganisme uji. Metode isolasi dilakukan dengan menyebarkan hasil pengenceran 10 sampel liken pada medium agar HV, YIM 6, dan YIM 711. Identifikasi molekuler dengan menganalisis gen 16S rRNA. Penapisan aktivitas antimikroba dilakukan dengan metode difusi keping agar terhadap lima mikoorganisme uji; Bacillus subtilis BTCC B.612, Escherichia coli BTCC B.614, Candida albicans BTCC Y.33, Staphylococcus aureus BTCC B.611, dan Micrococcus luteus BTCC B.552. Isolat dengan potensi aktivitas antimikroba terhadap lebih dari satu mikroorganisme uji dipilih untuk penapisan ekstrak. Penapisan ekstrak aktinomisetes potensial dilakukan dengan metode difusi cakram. Analisis senyawa dilakukan dengan menentukan nilai Minimal Inhibitory Concentration (MIC), bioassay hasil fraksinasi ekstrak, dan menganalisis senyawa aktif menggunakan Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS). Sebanyak 125 isolat aktinomisetes dihasilkan pada proses isolasi. Berdasarkan dentifikasi molekular, 69 isolat termasuk dalam 6 familia, 7 genus, dan 31 species.Hasil penapisan menunjukkan terdapat 24 isolat dengan daya hambat terhadap mikroorganisme uji.Tiga isolat menunjukkan aktivitas antimikroba pada lebih dari satu miroorganisme uji yaitu LC-23, LC-94, dan LC-100. Hasil pengujian ekstrak menunjukkan LC-23, LC-94, dan LC-100 memiliki daya hambat terhadap Staphylococcus aureus BTCC B.611 dan Micrococcus luteus BTCC B.552. Nilai MIC ekstrak terhadap Staphylococcus aureus BTCC B.611;LC-23 kurang dari 2,02 mg/L, LC-94 sebesar 8,31 mg/L, LC-100 sebesar 30.25 mg/L. Sementara nilai MIC terhadap Micrococcus luteusBTCC B.552; LC-23 kurang dari 2,02 mg/L, LC-94 sebesar 8,31 mg/L, dan LC-100 sebesar 60,5 mg/L. Hasil pengujian LC-MS/MS dilakukan pada hasil fraksinasi ekstrak LC-23,diidentifikasi sebagai senyawa 1-methyl-2-[(Z)-8-tetradecenyl]4(1H)-quinolone, Bufotalinin, Neoline-1, dan Protodiosgenin serta beberapa senyawa yang diduga baru.

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ABSTRACT

Actinomycetes are able to produce beneficial antibiotics. Actinomycetes can also be isolated from any kind of environment such as tree lichen. This research aims to find out the diversity of the actinomycetes isolated from lichens collected in Cibinong Science Center (CSC) and Cibodas Botanical Garden (CBG) areas and analyze the profile of secondary metabolite of isolates towards experimented microorganisms. Isolation was caried out using spread dilution method on HV, YIM 6, and YIM 11 agar media. Molecular identification was done by analyzing the 16S rRNA gene. Screening for antimicrobial activity used agar plug diffusion method against Bacillus subtilis BTCC B.612, Escherichia coli BTCC B.614, Candida albicans BTCC Y.33, Staphylococcus aureus BTCC B.611, and Micrococcus luteus BTCC B.552. The isolate that has potential for antimicrobial activity against more than one test microorganism was chosen for screening of extract. Screening for potential actinomycetes extract was done using disc diffusion method. The analysis of compoundwas carried out by determining the Minimal Inhibitory Concentration (MIC), bioassay as extract fractionation product, and measured by Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS). A total 125 actinomycetes isolates were produced during the isolation process. Based on the molecule identification, 69 isolates belong to 6 familia, 7 genus, and 31 species. The screening process showed that there were 24 isolates with inhibition activity against test microorganisms. There were 3 isolates showed microbial activity against more than one test microorganism; LC-23, LC94, and LC-100. The screening result showed that LC-23, LC94, and LC-100 had antimicrobial activity towards Staphylococcus aureus BTCC B.611 and Micrococcus luteus BTCC B.552. The MIC value towards Staphylococcus aureus BTCC B.611; LC-23 is less than 2,02 mg/L, LC-94 has 8.31 mg/L, and LC-100 has 30.25 mg/L. The MIC value towards Micrococcus luteus BTCC B.552; LC-23 is less than 2.02 mg/L, LC-94 has 8.31 mg/L, and LC-100 has 60.5 mg/L. The LC-MS/MS analysis was done on the fractionation product of LC-23 which was identified as 1-methyl-2-[(Z)-8-tetradecenyl]4(1H)-quinolone, Bufotalinin, Neoline-1, and Protodiosgenin compounds and unnamed compounds.