Penapisan Aktivitas Antibakteri dan Karakterisasi Isolat Bakteri Asal Situ Gunung, Sukabumi

Abstract

Pencarian sumber antibiotik baru diperlukan seiring dengan peningkatan kasus resistensi bakteri patogen terhadap antibiotik. Danau dan curug di Situ Gunung diharapkan dapat menjadi sumber bakteri potensial penghasil senyawa bioaktif. Sebanyak 21 isolat bakteri telah diisolasi dari lingkungan tersebut, tetapi belum dikaji potensinya sebagai penghasil antibakteri. Penelitian ini bertujuan untuk mengarakterisasi dan menganalisis potensi isolat bakteri tersebut sebagai bakteri penghasil antibakteri. Uji antibakteri dengan metode kultur ganda (dual culture) menunjukkan bahwa 3 isolat bakteri (kode: AT 2.12, AT 2.4, AT 1.2) mampu menghambat pertumbuhan Staphylococcus aureus dengan indeks penghambatan yang bervariasi berkisar antara 0,75 - 2,5, namun 21 isolat tersebut tidak dapat menghambat pertumbuhan Escherichia coli. Isolat AT 2.12 memiliki indeks penghambatan terbesar yaitu 2,5. Tiga isolat terpilih memiliki karakter non hemolitik pada media blood agar. Karakterisasi morfologi sel dengan pewarnaan Gram menunjukkan bahwa dua isolat potensial AT 2.12 dan AT 2.4 berturut-turut merupakan Gram negatif dan Gram positif. Kata kunci : antibiotik, bakteri akuatik, Escherichia coli, Situ Gunung, Staphylococcus aureus,

The searching for new antibiotics sources is needed along with the increasing cases of resistance of pathogenic bacteria to antibiotics. Lakes and waterfalls in Situ Gunung are expected to be a potential sources of bacteria producing bioactive compounds. A total of 21 bacterial isolates have been isolated from the environment, but their potential as antibacterial producers has not been studied yet. This study was designed to screen and characterize antibacterial producing bacteria. Antibacterial test using dual culture method showed that 3 bacterial isolates namedly AT 2.12, AT 2.4, AT 1.2 were able to inhibit the growth of Staphylococcus aureus with an inhibitory index that varied between 0.75 - 2.5, but the 21 isolates could not inhibit the growth of Escherichia coli. AT 2.12 isolate showed the largest inhibitory index of 2.5. Three selected isolates had non-hemolytic characters on blood agar medium. Cell morphology characterized by Gram staining showed that two potential isolates coded as AT 2.12 and AT 2.4 were Gram negative and Gram positive group, respectively. Keywords: antibiotic, aquatic bacteria, Escherichia coli, Situ Gunung, Staphylococcus aureus