Potensi Quorum Quencher Bakteri Filosfer dan Rizosfer terhadap Dickeya dadantii

Abstract

<p>Ekspresi gen-gen virulensi pada Dickeya dadantii diatur oleh proses quorum sensing menggunakan asil-homoserin lakton (AHL) sebagai molekul sinyal. Patogenisitas bakteri tersebut dapat dihambat oleh aktivitas quorum quenching (QQ) bakteribakteri penghasil AHL-laktonase. Tujuan penelitian ini adalah mengisolasi dan mengarakterisasi bakteri penghasil AHLlaktonase asal rizosfer dan filosfer yang berpotensi untuk dikembangkan sebagai quorum quencher untuk D. dadantii. Isolasi bakteri dilakukan dari sampel daun dan sampel tanah rizosfer beberapa komoditas tanaman asal Sukabumi, Tegal, Kupang, dan Wonosobo. Sebanyak 8 dari 79 isolat bakteri yang diperoleh menunjukkan aktivitas QQ terhadap bioindikator Chromobacterium violaceum. Bioasai respons hipersensitif (hypersensitive response) yang dilakukan pada tanaman tembakau<br />menunjukkan enam (KT2, KT9, KT10, KUT1, TKF2, and WKF3) dari delapan isolat tersebut tidak menimbulkan respons hipersensitif. Keenam isolat tersebut mampu menekan virulensi D. dadantii pada umbi kentang. Sekuen 16S rRNA enam isolat tersebut memiliki kemiripan tertinggi dengan Bacillus cereus, B. aryabhattai, B. acidiceler, dan Micrococcus aloeverae. B. cereus KT9 and B. aryabhattai TKF2 terdeteksi memiliki gen penyandi AHL-laktonase (aiiA). Ini merupakan laporan yang pertama tentang aktivitas QQ pada spesies M. aloeverae, B. aryabhattai, and B. acidiceler. Keberadaan gen aiiA pada B.<br />aryabhattai juga belum pernah dilaporkan sebelumnya. Penelitian ini memberikan informasi baru tentang aktivitas QQ ketiga isolat tersebut dan potensinya sebagai quorum quencher untuk D. dadantii.</p>

Phyllosphere bacteria with antiquorum sensing and antibiofilm activities against fish pathogenic bacteria

“…The DNA was amplified using the following steps: pre-denaturation at 94 °C for 5 min, 30 cycles of 30 s denaturation at 95 °C, annealing at 55 °C for 30 s, elongation at 72 °C for 30 s and the post elongation 72 °C for 7 min. After that, PCR product was separated using 1.5% agarose gel electrophoresis for 45 min with 80 V, then visualized [ 15 ]. The results were sequenced by Genetika Science and the results were submitted to GenBank.…”

Quantification of anti-quorum sensing and antibiofilm activity of Phyllosphere bacteria against food spoilage bacteria

“…Phyllosphere bacteria can produce bioactive compounds that can inhibit the process of quorum sensing. For example, this bacteria can fight phytopathogenic Dickeya dadantii by inhibiting of quorum sensing through production of AHL-lactonase as quorum quencher (Satwika et al 2017). The new discoveries can be made regarding phyllosphere bacteria as an anti-biofilm that can be done by interfering quorum sensing or destruction of biofilms that have been formed.…”

Screening and quantification of anti-quorum sensing and antibiofilm activities of phyllosphere bacteria against biofilm forming bacteria

“…Phyllosphere bacteria, which lives the most on the leaves surface area, reported to have potential in quorum quenching activity with produce molecules such as AHL lactonase enzyme [4–6]. High populations of phyllosphere bacteria show activities such as antimicrobial and antibiofilm that produced to survive on the leaves surface area [7].…”