Isolasi, Kajian Keragaman, dan Aktivitas Antioksidan Aktinobakteri Endofit Bawang Dayak (Eleutherine palmifolia L. Merr)

Abstract

Bawang dayak merupakan tanaman khas Kalimantan yang berkhasiat sebagai antioksidan. Tanaman ini merupakan salah satu sumber potensial mikroorganisme endofit penghasil antioksidan. Penelitian ini bertujuan mengisolasi, mengkaji keragaman, dan menguji aktivitas antioksidan aktinobakteri bawang dayak. Tujuh isolat aktinobakteri telah berhasil diisolasi dari umbi bawang dayak menggunakan medium HVA. Berdasarkan karakter morfologi koloni, miselia aerial, dan penataan sporanya, isolat tersebut diduga termasuk kelompok Streptomyces sp. Uji aktivitas antioksidan menggunakan DPPH menunjukkan bahwa aktivitas antioksidan supernatan isolat-isolat tersebut memiliki aktivitas antioksidan dengan persen inhibisi berkisar antara 38,8% hingga 102,6%. Isolat EPB5 memiliki aktivitas antioksidan tertinggi sebesar 102,6%. Dengan demikian, tujuh isolat aktinobakteri tersebut berpotensi sebagai sumber antioksidan.

Dayak onion (Eleutherine palmifolia L. Merr) is a typical Kalimantan herbaceous plant which is well known as a source of antioxidant. This plant could be a great source of endophytic microbes producing antioxidant compounds. The present study was aimed to isolate and analyze the morphological diversity of E. palmifolia endophytic actinobacteria as well as their antioxidant properties. Seven actinobacteria isolates have successfully been isolated from Dayak onion bulbs using HVA medium. Based on the morphological characteristics in different media and the type of their spore chains, it was assumed that these isolates belonged to the genus Streptomyces sp. As tested by DPPH analysis, supernatant derived from these isolates showed antioxidant activity with inhibition percentage ranging from 38,8% to 102,6%. The highest antioxidant activity exhibited by EPB5 isolate. In conclusion, all these isolates could be further studied and developed as the alternative source of antioxidant.