Isolation and molecular identification of Endophytic bacteria from Noni fruits (Morinda citrifolia l.) and their antibacterial activity

Abstract

Endophytic bacteria are microorganisms that exist in the system of plant tissues such as fruits, leaves, twigs, roots and they can form colonies without causing damage to the plant. One potential medicinal plant has endophytic bacteria are Noni fruits (Morinda citrifolia l). This study aimed at isolating endophytic bacterial from Noni fruits (Morinda citrifolia l), screening endophytic bacteria, determining antibacterial activity of potential endophytic bacteria, identifying 16S rRNA of potential endophytic bacteria, and detection of an antibacterial compound using GCMS. Endophytic bacteria were successfully isolated from Noni fruits and disc-diffusion methods were used to screen for antibacterial activity against pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Shigella dysenteriae, and Streptococcus mutans). The result of bacterial activity showed isolate ACP1, ACP2, ACP4, and ACP6 were produced antibacterial compounds. The activity shown with the formation of a clear zone and ACP6 isolate could inhibit four pathogenic bacteria with the highest clear zone. Molecular identification was investigated used PCR amplification 16S rRNA gene. The result showed that the potential isolate ACP6 (Acc. No. MH915674.1) belonging as Enterobacter cloacae with 99 % sequence similarities and according to GCMS analysis, ethyl acetate fraction from secondary metabolite ACP6 contains Pyrazine as a bioactive compound. These findings suggest that the identified strains may contribute to the search for new sources of antibacterial substances.