Bioproduction of Antioxidant Chemical Compounds from Endophytic Bacteria of Red Betel Plants (Piper cf. fragile. Benth)

Abstract

<em>Endophytic bacteria living in plant tissues can produce the same secondary metabolite compounds as their host plants. Endophytic bacteria obtained from the red betel plant (</em>Piper cf. fragile<em> Benth) have the potential to produce antioxidant compounds. This research aimed to select endophytic bacteria that had antioxidant activity derived from leaves, stems, and roots of red betel. Each isolate was fermented in NB (Nutrient Broth) medium for 24 hours. </em><em>The fermentation results were separated between supernatant and biomass. The supernatant was extracted with ethyl acetate and then assayed for antioxidant activity qualitatively and quantitatively by free radical attenuation method using ABTS reagent (2,2-Azinobis(3-etilbenzatiazolin)-6-sulfonat acid). The results showed that, from 15 isolates of red betel endophytic bacteria, four isolates showed qualitative antioxidant activity. Isolates of SMB1 and SMD3.1 had IC<sub>50</sub> values of 23.11 and 94.88 ppm, respectively (IC<sub>50 </sub>value of trolox as control was 4,041 ppm). The quantitative test results of the selected extract of SMB1 isolate analyzed with GC-MS (Gas Chromatography-Mass Spectrometry), allegedly contained 1,2-Benzenediccarboxylic acid, bis(2-ethylhexyl) ester compound with a similarity percentage of 93% and had strong antioxidant activity.</em>