Characterisation and identification of antibacterial compound from marine actinobacteria: In vitro and in silico analysis

Abstract

Objective: The present study was focused on the characterization and in silico analysis of antibacterial compound derived from marine actinobacteria isolated from the sediments of salterns of Ongole, Andhra Pradesh, India. Methods: The sediment sample was serially diluted and marine actinobacteria were isolated in actinomycetes isolation agar. A total of 9 colonies were recovered and among them, 5 morphologically distinct isolates were selected for further processing. The antibacterial activity of these five isolates was tested against 4 clinical isolates collected from Narayani Hospital, Vellore, Tamil Nadu. Results: The isolate SJP4 showed inhibitory activity against all the test pathogens viz., Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus cereus. The structure of the compounds extracted from SJP4 was identified as 8-diaza-2,9-dibenzoyl-5,6-diphenyl-2,8-decadienedioic acid diethyl ester and [1,2,4]triazol-1-ylethanone through GCMS analysis. Molecular docking studies was done using Autodock software. These two compounds were docked into the binding site of DNA gyrase and found to have binding energy of −6.55(Kcal/mol) and −4.86(Kcal/mol) respectively. The potential actinobacteria isolate was identified as Nocardiopsis dassonvillei SJPB4 strain (Accession no. MG434671) using 16 s rRNA sequencing. Conclusion: We are concluding that as the compounds were successfully docked on to the active site of DNA gyrase. Keywords: Marine actinobacteria, Antibacterial activity, Molecular docking, DNA gyrase, PRX1