Biological potential of secondary metabolites extracted from a marine bacterial isolate Acinetobacter baumannii (MP-1) against Serratia marcescens

Bacterial biofilms can cause severe infections in host organisms, and they display increased drug tolerance. A novel therapeutic strategy is required to overcome the existing issues. Screening of novel specialized metabolites from bacterial communities has gained significant attention and is being utilized for various biological claims. Hence, this study aims to screen specialized metabolites from Acinetobacter baumannii . The octanoic acid-rich fractions extracted from A. baumannii M1 were characterized and confirmed by Fourier Transform Infrared Spectroscopy and Gas Chromatography-Mass Spectrometry techniques. The minimum inhibitory concentration of the octanoic acid against Serratia marcescens was observed from 30 µg/ mL. Most importantly, 60.39% of biofilm inhibition was observed at 400 µg/ mL concentration and it was confirmed using microtiter plate and tube assay methods. Further, 400 µg/ mL of octanoic acid inhibited 61.3% of biofilm on stainless steel plates. The molecular docking of octanoic acid against Serratia’ s proteins7M5F and 3CSL resulted in moderate docking scores with binding affinities. Conclusively, research outcomes demonstrated that octanoic acid-rich fractions from A. baumannii have the ability to inhibit the growth of S. marcescens by hindering its movement, enzyme production, biofilm formation, and other virulent and non-virulent factors. Overall, results demonstrated that octanoic acid may serve as an effective agent to control S. marcescens infections. • The specialized metabolite-rich fractions from Acinetobacter baumannii were collected. • The bactericidal and biofilm-inhibiting properties were tested using the metabolites against Serratia marcescens . • The MIC value was found to be 30 µg/ mL against Serratia marcescens . • A dose-dependent biofilm inhibition was observed among the tested concentrations.