Metabolisme Dibenzofuran oleh Paenibacillus sp. strain GMD1

KUSUMANINGTYAS, Pintaka, Ir. Jaka Widada, MP.,Ph.D

2005 | Tesis | S2 Bioteknologi

Dibenzofuran (DBF) merupakan senyawa xenobiotik yang dihasilkan sebagai produk samping yang tak diinginkan dari berbagai proses industri, pembakaran limbah industri dan sampah serta tersebar di lingkungan sebagai polutan. Senyawa ini sangat rekalsitran terhadap degradasi biologis di alam dan mudah mengalami klorinasi menghasilkan dibenzofuran terklorinasi yang sangat toksik dan karsinogenik. Untuk mengatasi lingkungan yang terpolusi senyawa ini, bioremediasi dengan bioaugmentasi merupakan upaya yang tepat dan efektif. Oleh karena itu isolasi, karakterisasi dan identifikasi isolat- isolat bakteri pendegradasi DBF sangat penting dalam pengembangan teknologi bioremediasi dibenzofuran. Laboratorium Mikrobiologi Tanah dan Lingkungan Universitas Gadjah Mada telah berhasil mengisolasi 12 isolat bakteri dari tanah hutan bakau pantai utara, kabupaten Indramayu, Jawa Barat yang mampu tumbuh dengan dibenzofuran sebagai satu-satunya sumber karbon. Penelitian ini bertujuan untuk mengkarakterisasi, mengidentifikasi dan menentukan jalur degradasi DBF dari isolat-isolat terpilih. Kemampuan degradasi DBF dari 12 isolat ditentukan dengan analisis gas-chromatography (GC). Lima isolat terpilih dianalisis keragaman genetiknya dengan REP-PCR dan keragaman metabolitnya dengan kromatografi lapis tipis (KLT). Empat isolat bakteri terpilih diuji lebih lanjut mengenai pola pertumbuhan dan kecepatan degradasi DBF. Karakteristik biokimia dari isolat yang paling kuat kemampuan degradasinya dianalisis menggunakan BIOLOG EcoPlate dan diidentifikasi dengan sekuensing parsial gen 16S rDNA. Analisis jalur degradasi DBF dari isolat tersebut ditentukan dengan menganalisis senyawa-senyawa hasil degradasi menggunakan Gas Chromatography-Mass Spectrometry (GCMS). Hasil karakterisasi secara morfologis, fisiologis dan biokimiawi serta hasil analisis sekuen 16S rDNA menunjukkan bahwa isolat GMD1 yang memiliki kemampuan paling kuat dalam mendegradasi DBF ke dalam genus Paenibacillus sp. Analisis GCMS mengindikasikan bahwa isolat GMD1 memiliki jalur degradasi DBF melalui angular dioksigenasi seperti pada Sphingomonas wittichii galur RW1 dan Terrabacter sp. galur DBF63.

Dibenzofuran (DBF) is a xenobiotic compound that was produced as unwanted by product from various industrial processes and through combustion of industrial waste and dispersed in environment as a contaminant. This compound is highly recalcitrant to biological degradation in natural environments and susceptible to chlrorination to become chlorinated dibenzofuran that is a highly toxic and carcinogenic compound. For cleaning polluted environments by this compound, bioremediation has been carried out as a hopeful alternative strategy. Moreover, the isolation, characterization and identification of various DBFdegrading bacteria are important to improve the bioremediation technologies for DBF. Laboratory of Soil and Environmental Microbiology Gadjah Mada University has isolated 12 bacteria from mangrove forest at Indramayu, West Java. These isolates are able to utilize DBF as their sole carbon source. The purpose of this study was to characterize and identify as well as determining the DBF degradation pathway of the selected isolate. Capability of the 12 DBF-degrading isolates was determined by GC analysis. Five isolates selected were examined for their genetic diversity and metabolites diversity by REP-PCR analysis and TLC analysis, respectively. Four of the five isolates were subjected for further studied with respect to the correlation between their growth and DBF degradation rates. The isolate which has the highest ability to degrade DBF was biochemically characterized using BIOLOG EcoPlate. Identification of this isolate was further done by partial sequencing of 16S rDNA gene and the DBF degradation pathway was determined by GCMS analysis. Based on the morphological, physiological, biochemical characteristics and 16S rDNA gene sequences, isolate GMD1 which has the highest ability to degrade DBF was identified as Paenibacillus sp. GCMS analysis indicated that the isolate has the DBF degradation pathway via angular dioxygenation.

Kata Kunci : Bioteknologi,Bakteri Pendegradasi,DBF, characterization, identification, degrader bacteria, dibenzofuran, degradation pathway