Isolasi bakteri endofit dari akar tanaman pletekan (Ruellia tuberosa L) dan uji aktivitas antibakteri

ABSTRAK

Mikroba endofit merupakan mikroba yang hidup didalam jaringan tanaman tanpa mengubah fungsi normal dari jaringannya, serta mampu memproduksi metabolit sekunder yang sama dengan tanaman inang. Tanaman pletekan sebagai tanaman inang mampu memproduksi metabolit sekunder seperti flavonoid, tanin dan saponin yang berpotensi sebagai antibakteri, sehingga tanaman pletekan dapat digunakan sebagai sumber bakteri endofit yang berpotensi dalam memproduksi senyawa antibakteri.

Isolasi bakteri endofit akar tanaman pletekan dilakukan dengan menggunakan metode tempel (peace pant) dan sebar (spread plate). Isolat hasil isolasi diidentifikasi meliputi morfologi koloni, pewarnaan Gram, pewarnaan endospora dan uji katalase. Uji antibakteri in vitro dilakukan dengan menggunakan metode uji Kirby-bauer dan diukur zona hambat sebagai nilai aktivitas antibakteri.

Hasil penelitian didapatkan 5 isolat bakteri endofit akar tanaman pletekan yaitu isolat 1A, 1B, 1C, 1F dan 2C. Isolat hasil isolasi bakteri endofit akar tanaman pletekan merupakan golongan Gram positif, isolat 1C negatif endospora, isolat 1F negatif katalase dan endospora. Nilai aktivitas antibakteri terbesar terhadap bakteri Eschericia coli adalah isolat 2C sebesar 5,7 mm dan terhadap bakteri Staphylococcus aureus adalah isolat 1B sebesar 6,3 mm.

ABSTRACT

Endophytic bacteria is a microbe which lives inside the plant tissue without changing normal tissue function and capable to produce specific secondary metabolite which host plant produces. Pletekan plant as the host plant capacity to produce secondary metabolite such as flavonoids, tanin and saponins which are potential as antibacterial, therefore pletekan plant can be used as a source of potentially endophytic bacteria to produce antibacterial compound.

Isolation of endophytic bacteria from pletekan plant root was done by peace plant and spread plate method. The isolate of endophytic bacteria from pletekan plant root was identified by colony morphology, Gram stain, endospore stain and catalase test. In vitro antibacterial test was done by Kirby-Bauer method and measured inhibition zone as a number of antibacterial activity.

The result of this research was found 5 isolates endophytic bacteria from pletekan plant root those were, 1A, 1B and 2C were positive Gram, positive catalase and positive endospore. Isolate 1C was positive Gram, positive catalase and negative endospore, isolate 1F was positive Gram, negative catalase and endospore. The highest antibacterial activity against Escherichia coli was isolat 2C with inhibition diameter was 5.7 mm, against Staphylococcus aureus was isolate 1B with inhibition diameter was 6.3 mm.