Bioactive compound analysis and antioxidant activity of endophytic bacterial extract from Noni fruits (Morinda citrifolia L.)

Abstract

Endophytic bacteria have been recognised as a microorganism that has an important role as the producer of bioactive compounds. In the literature, endophytic bacteria from Noni fruits (Morinda citrifolia l.) with their antioxidant activities have been rarely studied. This research aimed at isolating endophytic bacteria associated with Noni fruits to investigate their antioxidant activity, to identify potential endophytic bacteria with16s rRNA and to detect bioactive compounds. Based on morphological characteristics of bacterial colonies, six endophytic bacteria were isolates from Noni fruits. The isolates were observed and evaluated in terms of their antioxidant activities using 1,1-Diphenyl-2-picryl-hydrazyl radical scavenging activity. Results of this study discovered supernatant from isolate ACP3 to have the highest 1,1-Diphenyl-2-picryl-hydrazyl free-radical scavenging activity up to 68.90%. In addition, molecular identification conducted by poly chain reaction amplification on 16S rRNA gene showed isolate ACP3 belong to Staphylococcus sp. with 100% sequence similarities. Looking at GCMS analysis, ethyl acetate fraction from the secondary metabolites of isolate ACP3 contained pyrazine alkaloids, which have been known as a bioactive compound. Based on these results, the ACP3 strain was considered as a good and sustainable resource for natural antioxidants.