Analisis Potensi Ekstrak Kasar Supernatan Bakteri Endofit Vetiveria zizanioides sebagai Penghambat Quorum Sensing pada Chromobacterium violaceum

• Main Author: Ayuningtiyas, Dwi Putri (Author)
• Format: Book
• Published: 2015-01-23.
• Subjects: Thesis; NonPeerReviewed
• Online Access: Link Metadata
• Notes: http://repository.upi.edu/16767/5/S_BIO_1000265_Title.pdf; http://repository.upi.edu/16767/6/S_BIO_1000265_Abstract.pdf; http://repository.upi.edu/16767/4/S_BIO_1000265_Table_of_content.pdf; http://repository.upi.edu/16767/8/S_BIO_1000265_Chapter1.pdf; http://repository.upi.edu/16767/9/S_BIO_1000265_Chapter2.pdf; http://repository.upi.edu/16767/1/S_BIO_1000265_Chapter3.pdf; http://repository.upi.edu/16767/2/S_BIO_1000265_Chapter4.pdf; http://repository.upi.edu/16767/3/S_BIO_1000265_Chapter5.pdf; http://repository.upi.edu/16767/7/S_BIO_1000265_Bibliography.pdf
• Keywords: L Education (General); QR Microbiology

Quorum sensing (QS) merupakan mekanisme komunikasi antar sel pada bakteri. QS bertanggung jawab dalam berbagai aktivitas biologis bakteri seperti bioluminansi, pembentukan biofilm, faktor virulensi, dan swarming. Potensi ekstrak kasar supernatan beberapa bakteri endofit Vetiveria zizanioides sebagai antimikroba menimbulkan pertanyaan mengenai pengaruh ekstrak-ekstrak tersebut terhadap QS. Percobaan dilakukan untuk mengetahui pengaruh ekstrak kasar supernatan bakteri endofit V. zizanioides terhadap QS pada Chromobacterium violaceum. Ekstrak kasar supernatan dari lima bakteri endofit yaitu Lysinibacillus sphaericus, Pantoea sp., Acinetobacter sp., Bacillus sp., dan Pseudomonas aeruginosa dengan konsentrasi 2,5; 3; dan 3,5 mg ml-1 diujikan pada kultur C. violaceum CV026 dalam medium Luria Bertani cair (Tryptone 1%, NaCl 1%, yeast extract 0,5%) dengan penambahan C6-HSL (1,2 µg ml-1). Kultur diinkubasi dalam suhu 27-28oC dengan digoyang dengan kecepatan 110 rpm selama 24 jam. Kadar violacein kemudian diamati dengan spektrofotometer menggunakan panjang gelombang 585 nm. Selain itu, untuk mengetahui aktivitas antimikroba dari masing-masing ekstrak juga dilakukan uji antimikroba dengan melakukan prosedur angka lempeng total. Hasil percobaan menunjukkan adanya penurunan kadar violacein oleh semua ekstrak kasar supernatan bakteri endofit pada seluruh seri konsentrasi. Penurunan kadar violacein pada perlakuan dengan ekstrak L. sphaericus, Pantoea sp. dan Acinetobacter sp. diikuti dengan penurunan jumlah bakteri C. violaceum CV026 viabel. Hal ini menunjukkan bahwa penurunan kadar violacein disebabkan karena aktivitas antimikroba dan bukan aktivitas anti QS. Pada perlakuan lainnya, yaitu ekstrak kasar supernatan bakteri endofit P.aeruginosa dan Bacillus sp., penurunan kadar violacein tidak diikuti oleh penurunan jumlah bakteri C. violaceum CV026 viabel. Hal ini sekaligus menunjukkan bahwa ekstrak kasar supernatan bakteri endofit kedua bakteri ini memiliki aktivitas anti QS pada C. violaceum. Aktivitas anti-QS paling optimum ditunjukkan oleh perlakuan dengan ekstrak kasar supernatan bakteri endofit Bacillus sp. dengan konsentrasi 3,5 mg ml-1. Quorum sensing (QS) is cell-to-cell communication mechanism in bacteria. QS regulates many bioactivity of bacteria such as biolumination, biofilm forming, virulence factors, and swarming. Antimicrobial activities of crude extract of some endophytic bacteria from Vetiveria zizanioides remains a question about their potency as quorum sensing inhibitor. An experiment was carried to know the effect of crude extract of supernatant from V. zizanioides endophytic bacteria to QS system in Chromobacterium violaceum. Crude extracts of five endophytic bacteria including Lysinibacillus sphaericus, Pantoea sp., Acinetobacter sp., Bacillus sp., dan Pseudomonas aeruginosa with concentration 2,5; 3; dan 3,5 mg ml-1 was tested into CV026 culture added by C6-HSL (1,2 µg ml-1). Cultures were incubated 27-28oC in temperature and 110 rpm of shaking for 24 hours. Violacein of each culture was measured by spectrophotometer in wavelength 585 nm. Total plate count procedure was also carried in order to find antimicrobial activity from each extract. The result shown a decreasing violacein content in all cultures treated by crude extract of five endophytic supernatant in all series of concentration (2,5; 3; 3,5 mg ml-1). The decreasing violacein content in treatment of crude extract of L. sphaericus, Pantoea sp., and Acinetobacter sp. were followed by the decreasing of total viable C. violaceum CV026. It showed that the decreasing violacein content was occurred because of antimicrobial activity and not anti QS activity. In other treatments, supernatant crude extract of two other bacteria including P. aeruginosa and Bacillus sp. were found to decreased violacein content without decreased total of viable C. violaceum CV026. It proved that the extract of these two bacteria have anti QS activity. The optimum inhibition of QS in C. violaceum was found in treatment of supernatant crude extract of Bacillus sp. with concentration 3,5 mg ml-1.