In Vitro Evaluation of the Antimicrobial, Antioxidant, and Cytotoxicity Potential Coupled with Molecular Docking Simulation of the Dynamic Fermentation Characteristics of Marine-Derived Bacterium Halomonas saccharevitans

Abstract

A variety of metabolites produced by marine microorganisms are gaining high value for their significant biological properties. Therefore, the search for active secondary metabolites from marine bacteria against pathogenic microorganisms has become essential for alternative and effective strategies. In this study, Halomonas saccharevitans, a marine-derived bacterium, was cultured and fermented on a liquid medium. The ethyl acetate (EtOAc) crude extract was then fractioned yielded five fractions to study their biological effect. Two fractions had significantly higher activity, i.e., absolute n-hexane against Staphylococcus aureus and Pseudomonas aeruginosa and absolute methanol (MeOH) against Escherichia coli and Bacillus subtilis, with promising MIC values. The time–kill kinetics assay for the very susceptible bacteria against active fractions was also examined. The antifungal assay of the active fractions had the highest activity against Aspergillus niger and Candida albicans with the examined variable MFC values. The cytotoxic assay against HepG2 cells showed promising activities, resulting in a 78% inhibition of cell viability. Moreover, the antioxidant activities showed reasonable inhibition values at 21.87 ± 0.85% and 98.25 ± 1.45%, compared to the control. Molecular docking revealed a high affinity between major detected compounds with free binding energies. The active fractions were characterized by the presence of diverse chemically esters, phenolics, essential oils, and other organic compounds detected by GC–MS. In conclusion, H. saccharevitans, derived from the Red Sea, might be useful as an alternative source for the possible production of bioactive substances with a variety of biomedical application.